XML 48 R56.htm IDEA: XBRL DOCUMENT v3.3.0.814
Investment Securities - Summary of Unrealized Losses on Held to Maturity Securities (Details)
$ in Thousands
Sep. 30, 2015
USD ($)
Investment
Dec. 31, 2014
USD ($)
Investment
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost $ 8,306,526 $ 7,421,042
Unrealized Gains 68,056 16,314
Unrealized Losses (7,579) (21,700)
Fair Value 8,367,003 7,415,656
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]    
Fair Value of Investments, Less than 12 months 1,043,761 3,438,894
Unrealized Losses, Less than 12 months (5,937) (16,520)
Fair Value of Investments, 12 months or longer 107,562 783,558
Unrealized Losses, 12 months or longer (1,642) (5,180)
Fair Value of Investments 1,151,323 4,222,452
Unrealized Losses $ (7,579) $ (21,700)
Number of held-to-maturity investments with unrealized loss | Investment 157 292.000
Number of held-to-maturity investments in continuous loss more than 12 months | Investment 63 26.000
U.S. agency debentures    
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost $ 545,753 $ 405,899
Unrealized Gains 11,923 4,589
Unrealized Losses 0 (38)
Fair Value 557,676 410,450
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]    
Fair Value of Investments, Less than 12 months   48,335
Unrealized Losses, Less than 12 months   (38)
Fair Value of Investments, 12 months or longer   0
Unrealized Losses, 12 months or longer   0
Fair Value of Investments   48,335
Unrealized Losses   (38)
Agency-issued mortgage-backed securities    
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 2,457,328 2,799,923
Unrealized Gains 18,925 5,789
Unrealized Losses (1,005) (2,320)
Fair Value 2,475,248 2,803,392
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]    
Fair Value of Investments, Less than 12 months 308,687 999,230
Unrealized Losses, Less than 12 months (438) (2,320)
Fair Value of Investments, 12 months or longer 23,732 0
Unrealized Losses, 12 months or longer (567) 0
Fair Value of Investments 332,419 999,230
Unrealized Losses (1,005) (2,320)
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate    
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 4,045,172 3,185,109
Unrealized Gains 24,146 4,521
Unrealized Losses (5,372) (14,885)
Fair Value 4,063,946 3,174,745
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]    
Fair Value of Investments, Less than 12 months 705,362 1,682,348
Unrealized Losses, Less than 12 months (5,264) (9,705)
Fair Value of Investments, 12 months or longer 8,945 783,558
Unrealized Losses, 12 months or longer (108) (5,180)
Fair Value of Investments 714,307 2,465,906
Unrealized Losses (5,372) (14,885)
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate    
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 109,478 131,580
Unrealized Gains 577 371
Unrealized Losses 0 0
Fair Value 110,055 131,951
Agency-issued commercial mortgage-backed securities    
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 1,073,160 814,589
Unrealized Gains 12,449 1,026
Unrealized Losses (309) (3,800)
Fair Value 1,085,300 811,815
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]    
Fair Value of Investments, Less than 12 months 0 629,840
Unrealized Losses, Less than 12 months 0 (3,800)
Fair Value of Investments, 12 months or longer 42,179 0
Unrealized Losses, 12 months or longer (309) 0
Fair Value of Investments 42,179 629,840
Unrealized Losses (309) (3,800)
Municipal bonds and notes    
Schedule of Held-to-maturity Securities [Line Items]    
Amortized Cost 75,635 83,942
Unrealized Gains 36 18
Unrealized Losses (893) (657)
Fair Value 74,778 83,303
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]    
Fair Value of Investments, Less than 12 months 29,712 79,141
Unrealized Losses, Less than 12 months (235) (657)
Fair Value of Investments, 12 months or longer 32,706 0
Unrealized Losses, 12 months or longer (658) 0
Fair Value of Investments 62,418 79,141
Unrealized Losses $ (893) $ (657)