Fair Value Measurements Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Level 1 [Member]
Mortgages loans held for sale	$ 0	$ 0
Available for sale investment securities	34,586	40,070
Other finanical assets	13,130	13,582
Total assets	47,716	53,652
Other financial liabilities	13,130	13,582
Level 1 [Member] \| Equity Securities [Member]
Available for sale investment securities	34,586	40,070
Level 1 [Member] \| U.S. Government Securities [Member]
Available for sale investment securities	0	0
Level 1 [Member] \| U.S. Government-Sponsored Agency Securities [Member]
Available for sale investment securities	0	0
Level 1 [Member] \| State and Municipal Securities [Member]
Available for sale investment securities	0	0
Level 1 [Member] \| Corporate Debt Securities [Member]
Available for sale investment securities	0	0
Level 1 [Member] \| Collateralized Mortgage Obligations [Member]
Available for sale investment securities	0	0
Level 1 [Member] \| Mortgage-Backed Securities [Member]
Available for sale investment securities	0	0
Level 1 [Member] \| Auction Rate Securities [Member]
Available for sale investment securities	0	0
Level 2 [Member]
Mortgages loans held for sale	47,009	83,940
Available for sale investment securities	2,321,748	2,443,475
Other finanical assets	3,901	9,256
Total assets	2,372,658	2,536,671
Other financial liabilities	2,734	760
Level 2 [Member] \| Equity Securities [Member]
Available for sale investment securities	0	0
Level 2 [Member] \| U.S. Government Securities [Member]
Available for sale investment securities	334	1,649
Level 2 [Member] \| U.S. Government-Sponsored Agency Securities [Member]
Available for sale investment securities	4,073	5,058
Level 2 [Member] \| State and Municipal Securities [Member]
Available for sale investment securities	322,018	349,563
Level 2 [Member] \| Corporate Debt Securities [Member]
Available for sale investment securities	114,017	111,675
Level 2 [Member] \| Collateralized Mortgage Obligations [Member]
Available for sale investment securities	1,001,209	1,104,058
Level 2 [Member] \| Mortgage-Backed Securities [Member]
Available for sale investment securities	880,097	871,472
Level 2 [Member] \| Auction Rate Securities [Member]
Available for sale investment securities	0	0
Level 3 [Member]
Mortgages loans held for sale	0	0
Available for sale investment securities	234,500	273,790
Other finanical assets	0	0
Total assets	234,500	273,790
Other financial liabilities	0	0
Level 3 [Member] \| Equity Securities [Member]
Available for sale investment securities	0	0
Level 3 [Member] \| U.S. Government Securities [Member]
Available for sale investment securities	0	0
Level 3 [Member] \| U.S. Government-Sponsored Agency Securities [Member]
Available for sale investment securities	0	0
Level 3 [Member] \| State and Municipal Securities [Member]
Available for sale investment securities	0	0
Level 3 [Member] \| Corporate Debt Securities [Member]
Available for sale investment securities	9,289	13,111
Level 3 [Member] \| Collateralized Mortgage Obligations [Member]
Available for sale investment securities	0	0
Level 3 [Member] \| Mortgage-Backed Securities [Member]
Available for sale investment securities	0	0
Level 3 [Member] \| Auction Rate Securities [Member]
Available for sale investment securities	225,211	260,679
Total [Member]
Mortgages loans held for sale	47,009	83,940
Available for sale investment securities	2,590,834	2,757,335
Other finanical assets	17,031	22,838
Total assets	2,654,874	2,864,113
Other financial liabilities	15,864	14,342
Total [Member] \| Equity Securities [Member]
Available for sale investment securities	34,586	40,070
Total [Member] \| U.S. Government Securities [Member]
Available for sale investment securities	334	1,649
Total [Member] \| U.S. Government-Sponsored Agency Securities [Member]
Available for sale investment securities	4,073	5,058
Total [Member] \| State and Municipal Securities [Member]
Available for sale investment securities	322,018	349,563
Total [Member] \| Corporate Debt Securities [Member]
Available for sale investment securities	123,306	124,786
Total [Member] \| Collateralized Mortgage Obligations [Member]
Available for sale investment securities	1,001,209	1,104,058
Total [Member] \| Mortgage-Backed Securities [Member]
Available for sale investment securities	880,097	871,472
Total [Member] \| Auction Rate Securities [Member]
Available for sale investment securities	$ 225,211	$ 260,679

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details