Investment Securities (Details 2) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Expected remaining maturities of debt securities available-for-sale, fair value
Fair Value	$ 7,185,288	$ 5,720,675	$ 5,397,870
Total debt securities
Expected remaining maturities of debt securities available-for-sale, fair value
One year or less fair value	1,877,478
Over 1 year through 5 years, fair value	4,232,472
Over 5 years through 10 years, fair value	873,976
Over 10 years, fair value	199,547
Fair Value	7,183,473	5,710,239	5,387,843
Expected remaining maturities of debt securities available-for-sale, amortized cost
One year or less, amortized cost	1,873,133
Over 1 year through 5 years, amortized cost	4,113,671
Over 5 years through 10 years, amortized cost	859,144
Over 10 years, amortized cost	196,586
Total of debt securities available-for-sale, amortized cost	7,042,534
U.S. Treasury
Expected remaining maturities of debt securities available-for-sale, fair value
One year or less fair value	13,057
Over 1 year through 5 years, fair value	6,156
Fair Value	19,213	14,113	19,117
Federal agency - Debt
Expected remaining maturities of debt securities available-for-sale, fair value
One year or less fair value	1,507,394
Over 1 year through 5 years, fair value	382,696
Over 5 years through 10 years, fair value	13,598
Fair Value	1,903,688	1,142,328	1,311,936
Federal agency - MBS
Expected remaining maturities of debt securities available-for-sale, fair value
One year or less fair value	2,515
Over 1 year through 5 years, fair value	312,598
Over 5 years through 10 years, fair value	193,454
Over 10 years, fair value	32,658
Fair Value	541,225	551,346	508,508
CMOs - Federal agency
Expected remaining maturities of debt securities available-for-sale, fair value
One year or less fair value	294,079
Over 1 year through 5 years, fair value	3,307,328
Over 5 years through 10 years, fair value	516,243
Over 10 years, fair value	110,003
Fair Value	4,227,653	3,497,147	2,923,601
CMOs - Non-agency
Expected remaining maturities of debt securities available-for-sale, fair value
One year or less fair value	9,125
Over 1 year through 5 years, fair value	40,298
Over 5 years through 10 years, fair value	27,007
Fair Value	76,430	118,295	205,320
State and municipal
Expected remaining maturities of debt securities available-for-sale, fair value
One year or less fair value	46,448
Over 1 year through 5 years, fair value	168,028
Over 5 years through 10 years, fair value	102,270
Over 10 years, fair value	56,886
Fair Value	373,632	343,380	360,471
Other debt securities
Expected remaining maturities of debt securities available-for-sale, fair value
One year or less fair value	4,860
Over 1 year through 5 years, fair value	15,368
Over 5 years through 10 years, fair value	21,404
Fair Value	$ 41,632	$ 43,630	$ 58,890

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

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