XML 17 R33.htm IDEA: XBRL DOCUMENT v2.4.0.6
Investment Securities (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Available-for-Sale:    
Amortized Cost $ 3,227,554 $ 3,291,685
Gross Unrealized Gains 71,490 78,333
Gross Unrealized Losses (8,194) (2,461)
Fair Value 3,290,850 3,367,557
Held-to-Maturity:    
Amortized Cost 3,597,810 3,595,065
Gross Unrealized Gains 83,799 93,977
Gross Unrealized Losses (2,401) (1,366)
Fair Value 3,679,208 3,687,676
Debt Securities Issued by the U.S. Treasury and Government Agencies
   
Available-for-Sale:    
Amortized Cost 709,315 855,070
Gross Unrealized Gains 15,059 14,936
Gross Unrealized Losses (15) (17)
Fair Value 724,359 869,989
Held-to-Maturity:    
Amortized Cost 285,139 190,168
Gross Unrealized Gains 5,207 5,198
Fair Value 290,346 195,366
Debt Securities Issued by States and Political Subdivisions
   
Available-for-Sale:    
Amortized Cost 799,521 753,207
Gross Unrealized Gains 25,942 30,159
Gross Unrealized Losses (2,227) (955)
Fair Value 823,236 782,411
Debt Securities Issued by Corporations
   
Available-for-Sale:    
Amortized Cost 187,399 82,450
Gross Unrealized Gains 1,991 1,984
Gross Unrealized Losses (834)  
Fair Value 188,556 84,434
Held-to-Maturity:    
Amortized Cost 23,544 24,000
Gross Unrealized Gains   4
Gross Unrealized Losses (172)  
Fair Value 23,372 24,004
Residential Mortgage-Backed Securities issued by U.S. government agencies
   
Available-for-Sale:    
Amortized Cost 919,419 1,041,669
Gross Unrealized Gains 25,337 27,283
Gross Unrealized Losses (394) (292)
Fair Value 944,362 1,068,660
Held-to-Maturity:    
Amortized Cost 3,260,767 3,349,403
Gross Unrealized Gains 76,752 86,673
Gross Unrealized Losses (2,229) (1,366)
Fair Value 3,335,290 3,434,710
Residential Mortgage-Backed Securities Issued by U.S. Government Sponsored Enterprises
   
Available-for-Sale:    
Amortized Cost 31,538 35,234
Gross Unrealized Gains 1,860 2,064
Fair Value 33,398 37,298
Held-to-Maturity:    
Amortized Cost 28,360 31,494
Gross Unrealized Gains 1,840 2,102
Fair Value 30,200 33,596
Commercial Mortgage-Backed Securities Issued by Government Agencies
   
Available-for-Sale:    
Amortized Cost 580,362 524,055
Gross Unrealized Gains 1,301 1,907
Gross Unrealized Losses (4,724) (1,197)
Fair Value 576,939 524,765
Mortgage-Backed Securities
   
Available-for-Sale:    
Amortized Cost 1,531,319 1,600,958
Gross Unrealized Gains 28,498 31,254
Gross Unrealized Losses (5,118) (1,489)
Fair Value 1,554,699 1,630,723
Held-to-Maturity:    
Amortized Cost 3,289,127 3,380,897
Gross Unrealized Gains 78,592 88,775
Gross Unrealized Losses (2,229) (1,366)
Fair Value $ 3,365,490 $ 3,468,306