Quarterly report pursuant to Section 13 or 15(d)

Available-for-Sale Securities, Weighted Average Life Classifications (Details)

v3.5.0.2
Available-for-Sale Securities, Weighted Average Life Classifications (Details) - USD ($)
$ in Thousands
Jun. 30, 2016
Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value $ 94,035  
Available-for-sale Securities, Debt Maturities, Year Two Through Three, Fair Value 297,880  
Available-for-sale Securities, Debt Maturities, Year Four Through Five, Fair Value 8,909,106  
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value 3,983,515  
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value 372,074  
Available-for-sale Securities 13,656,610 $ 7,825,320
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value 2,337  
Available-for-sale Securities, Debt Maturities, Year Two Through Three, Fair Value 104,436  
Available-for-sale Securities, Debt Maturities, Year Four Through Five, Fair Value 8,769,579  
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value 3,131,270  
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value 1,747  
Available-for-sale Securities 12,009,369 5,972,890
Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value 91,698  
Available-for-sale Securities, Debt Maturities, Year Two Through Three, Fair Value 193,444  
Available-for-sale Securities, Debt Maturities, Year Four Through Five, Fair Value 139,527  
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value 852,245  
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value 370,327  
Available-for-sale Securities $ 1,647,241 $ 1,852,430