v2.3.0.15
Available-For-Sale Securities (Summary Of Available-For-Sale Debt Securities By Contractual Maturity) (Details) (USD $)
In Thousands
Sep. 30, 2011
Dec. 31, 2010
Available-For-Sale Securities [Abstract]  
Less than one year, Amortized Cost$ 1,732,877$ 1,726,095
Greater than one year but less than five years, Amortized Cost3,103,0553,022,744
Greater than five years but less than ten years, Amortized Cost32,16033,076
Greater than ten years, Amortized Cost101,716142,338
Total, Amortized Cost4,969,8084,924,253
Less than one year, Fair Value1,737,0321,729,735
Greater than one year but less than five years, Fair Value3,090,5323,044,114
Greater than five years but less than ten years, Fair Value32,70333,580
Greater than ten years, Fair Value96,479137,078
Total, Fair Value$ 4,956,746$ 4,944,507