Quarterly report pursuant to Section 13 or 15(d)

Fair Value, Measurement Inputs, Disclosure (Details)

v3.10.0.1
Fair Value, Measurement Inputs, Disclosure (Details) - USD ($)
$ in Thousands
Sep. 30, 2018
Jun. 30, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Debt Securities, Available-for-sale, Categorized as Level 2 Assets 99.80%          
Debt Securities, Available-for-sale, Categorized as Level 3 Assets 0.20%          
Assets Reported at Fair Value, Debt Securities, Available-for-sale 92.50%          
Mortgage Servicing Rights Categorized as Level 3 Assets 100.00%          
Mortgage Loans Held-for-sale Categorized as Level 2 Assets 1.70%          
Mortgage Loans Held-for-sale Categorized as Level 3 Assets 98.30%          
Interest Rate Swaps, Swaptions and Credit Default Swaps Categorized as Level 2 Assets (Liabilities) 100.00%          
Short U.S. Treasury and Inverse Interest-only Securities Categorized as Level 2 Assets 100.00%          
Agency To-be-Announced Securities Categorized as Level 1 Assets (Liabilities) 100.00%          
Mortgage servicing rights $ 1,664,024 $ 1,450,261 $ 1,086,717 $ 930,613 $ 898,025 $ 693,815
Derivative assets, at fair value 403,231   309,918      
Equity securities 0   29,413      
Derivative liabilities, at fair value 797,504   31,903      
Fair Value, Measurements, Recurring [Member]            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 25,938,916   21,220,819      
Mortgage servicing rights 1,664,024   1,086,717      
Residential mortgage loans held-for-sale 27,537   30,414      
Derivative assets, at fair value 403,231   309,918      
Equity securities     29,413      
Total assets 28,033,708   22,677,281      
Derivative liabilities, at fair value 797,504   31,903      
Total liabilities 797,504   31,903      
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 0   0      
Mortgage servicing rights 0   0      
Residential mortgage loans held-for-sale 0   0      
Derivative assets, at fair value 15,212   913      
Equity securities     29,413      
Total assets 15,212   30,326      
Derivative liabilities, at fair value 43,314   1,930      
Total liabilities 43,314   1,930      
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 25,898,916   21,067,678      
Mortgage servicing rights 0   0      
Residential mortgage loans held-for-sale 456   474      
Derivative assets, at fair value 388,019   309,005      
Equity securities     0      
Total assets 26,287,391   21,377,157      
Derivative liabilities, at fair value 754,190   29,973      
Total liabilities 754,190   29,973      
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]            
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]            
Available-for-sale securities 40,000   153,141      
Mortgage servicing rights 1,664,024   1,086,717      
Residential mortgage loans held-for-sale 27,081   29,940      
Derivative assets, at fair value 0   0      
Equity securities     0      
Total assets 1,731,105   1,269,798      
Derivative liabilities, at fair value 0   0      
Total liabilities $ 0   $ 0