Schedule of Notional Amounts of Derivative Positions (Details) - USD ($)
|
3 Months Ended |
6 Months Ended |
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
$ 15,935,535,000
|
$ 26,390,596,000
|
$ 18,802,500,000
|
$ 21,998,381,000
|
| Additions |
4,347,586,000
|
15,731,304,000
|
7,704,409,000
|
31,277,266,000
|
| Settlement, Termination, Expiration or Exercise |
(3,295,005,000)
|
(15,980,530,000)
|
(9,518,793,000)
|
(27,134,277,000)
|
| End of Period Notional Amount |
16,988,116,000
|
26,141,370,000
|
16,988,116,000
|
26,141,370,000
|
| Average Notional Amount |
19,548,102,000
|
24,908,389,000
|
18,693,638,000
|
23,741,682,000
|
| Realized Gain (Loss), net |
(75,908,000)
|
(42,348,000)
|
17,486,000
|
8,109,000
|
| Inverse Interest-Only Securities [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
|
|
740,844,023
|
|
| Additions |
0
|
0
|
0
|
0
|
| Settlement, Termination, Expiration or Exercise |
(39,057,690)
|
(47,860,222)
|
(81,075,971)
|
(97,171,043)
|
| End of Period Notional Amount |
659,768,052
|
|
659,768,052
|
|
| Realized Gain (Loss), net |
0
|
0
|
0
|
0
|
| Interest Rate Swap [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Additions |
4,476,986,000
|
5,264,513,000
|
13,529,809,000
|
12,102,026,000
|
| Settlement, Termination, Expiration or Exercise |
(7,964,707,000)
|
(6,993,026,000)
|
(19,136,153,000)
|
(12,673,832,000)
|
| Realized Gain (Loss), net |
(39,626,000)
|
(26,297,000)
|
11,520,000
|
6,302,000
|
| Credit Default Swap [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Additions |
|
0
|
|
10,000,000
|
| Settlement, Termination, Expiration or Exercise |
|
(100,000,000)
|
|
(110,000,000)
|
| Realized Gain (Loss), net |
|
0
|
|
412,000
|
| Interest Rate Swaption [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Additions |
(375,000,000)
|
600,000,000
|
(4,255,000,000)
|
2,600,000,000
|
| Settlement, Termination, Expiration or Exercise |
5,605,000,000
|
(4,000,000,000)
|
5,380,000,000
|
(6,000,000,000)
|
| Realized Gain (Loss), net |
9,543,000
|
(28,819,000)
|
24,428,000
|
(30,789,000)
|
| Forward Contracts [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Additions |
(1,039,400,000)
|
121,000,000
|
(4,125,400,000)
|
4,436,000,000
|
| Settlement, Termination, Expiration or Exercise |
892,400,000
|
(2,095,000,000)
|
4,474,400,000
|
(5,070,000,000)
|
| Realized Gain (Loss), net |
(31,021,000)
|
12,901,000
|
(42,427,000)
|
31,751,000
|
| Options Held [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Additions |
1,285,000,000
|
8,897,000,000
|
2,555,000,000
|
10,897,000,000
|
| Settlement, Termination, Expiration or Exercise |
(1,770,000,000)
|
(2,000,000,000)
|
(134,000,000)
|
(2,000,000,000)
|
| Realized Gain (Loss), net |
(14,623,000)
|
(1,348,000)
|
24,146,000
|
(1,348,000)
|
| Total Return Swap [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
|
|
90,593,000
|
|
| Additions |
0
|
0
|
0
|
0
|
| Settlement, Termination, Expiration or Exercise |
(18,639,644)
|
(280,108,230)
|
(21,963,448)
|
(301,381,510)
|
| End of Period Notional Amount |
68,629,000
|
|
68,629,000
|
|
| Realized Gain (Loss), net |
(181,000)
|
523,000
|
(181,000)
|
523,000
|
| Loan Purchase Commitments [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Additions |
|
848,790,806
|
|
1,232,239,797
|
| Settlement, Termination, Expiration or Exercise |
|
(464,535,454)
|
|
(881,892,852)
|
| Realized Gain (Loss), net |
|
692,000
|
|
1,258,000
|
| Net Long [Member] | Inverse Interest-Only Securities [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
698,825,740
|
882,725,851
|
740,844,021
|
932,036,672
|
| End of Period Notional Amount |
659,768,000
|
834,866,000
|
659,768,000
|
834,866,000
|
| Average Notional Amount |
681,215,594
|
860,863,521
|
700,941,167
|
885,120,773
|
| Net Long [Member] | Interest Rate Swap [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
18,252,440,000
|
15,425,513,000
|
20,371,063,000
|
14,268,806,000
|
| End of Period Notional Amount |
14,764,719,000
|
13,697,000,000
|
14,764,719,000
|
13,697,000,000
|
| Average Notional Amount |
17,470,671,934
|
14,806,048,527
|
18,085,751,890
|
14,880,324,088
|
| Net Long [Member] | Credit Default Swap [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
|
125,000,000
|
|
125,000,000
|
| End of Period Notional Amount |
|
25,000,000
|
|
25,000,000
|
| Average Notional Amount |
|
112,912,088
|
|
119,670,329
|
| Net Long [Member] | Interest Rate Swaption [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
|
5,200,000,000
|
225,000,000
|
5,200,000,000
|
| End of Period Notional Amount |
1,350,000,000
|
1,800,000,000
|
1,350,000,000
|
1,800,000,000
|
| Average Notional Amount |
1,249,340,659
|
4,174,725,275
|
|
4,695,604,396
|
| Net Long [Member] | Forward Contracts [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
|
1,637,000,000
|
|
297,000,000
|
| Average Notional Amount |
|
189,230,769
|
|
171,219,780
|
| Net Long [Member] | Options Held [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
1,770,000,000
|
2,000,000,000
|
|
0
|
| End of Period Notional Amount |
1,285,000,000
|
8,897,000,000
|
1,285,000,000
|
8,897,000,000
|
| Average Notional Amount |
96,318,681
|
3,557,241,758
|
|
1,819,829,670
|
| Net Long [Member] | Total Return Swap [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
87,268,863
|
868,144,733
|
90,592,667
|
889,418,013
|
| End of Period Notional Amount |
68,629,000
|
588,037,000
|
68,629,000
|
588,037,000
|
| Average Notional Amount |
75,281,980
|
811,748,888
|
81,685,971
|
843,242,072
|
| Net Long [Member] | Loan Purchase Commitments [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
|
252,212,101
|
|
286,120,508
|
| End of Period Notional Amount |
|
636,467,000
|
|
636,467,000
|
| Average Notional Amount |
|
395,616,781
|
|
326,671,372
|
| Net Short Positions [Member] | Interest Rate Swaption [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
3,880,000,000
|
|
|
|
| Average Notional Amount |
|
|
98,922,652
|
|
| Net Short Positions [Member] | Forward Contracts [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
993,000,000
|
|
1,489,000,000
|
|
| End of Period Notional Amount |
1,140,000,000
|
$ 337,000,000
|
1,140,000,000
|
$ 337,000,000
|
| Average Notional Amount |
$ 24,728,275
|
|
12,430,939
|
|
| Net Short Positions [Member] | Options Held [Member] |
|
|
|
|
| Derivative, Notional Amount [Roll Forward] |
|
|
|
|
| Beginning of Period Notional Amount |
|
|
1,136,000,000
|
|
| Average Notional Amount |
|
|
$ 63,386,740
|
|