Available-For-Sale Securities (Contractual Maturities Of Available-For-Sale Securities) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010
Due in one year or less, Amortized Cost	$ 246,118	$ 647,494
Due in one year or less, Fair Value	246,435	647,987
Due in one to five years, Amortized Cost	495,758	309,795
Due in one to five years, Fair Value	497,409	310,663
Due in five to ten years, Amortized Cost	210,106	194,442
Due in five to ten years, Fair Value	209,120	185,938
Due after ten years, Amortized Cost	92,746	147,835
Due after ten years, Fair Value	95,172	149,782
Total available-for-sale securities, Amortized Cost	1,439,281	1,491,913
Total available-for-sale securities, Fair Value	1,456,426	1,496,302	1,418,035
Mortgage-Backed [Member]
Total available-for-sale securities, Amortized Cost	351,608	151,711
Total available-for-sale securities, Fair Value	365,323	161,681
Other Equity Securities [Member]
Total available-for-sale securities, Amortized Cost	42,945	40,636
Total available-for-sale securities, Fair Value	$ 42,967	$ 40,251