Securities (Schedule of Contractual Maturities of Investment Securities Available for Sale) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Available-for-sale Securities [Abstract]
Due within one year, Amortized Cost	$ 14,079
Due after one year through five years, Amortized Cost	303,875
Due after five years through ten years, Amortized Cost	487,643
Due after ten years, Amortized Cost	869,610
Total investment securities available-for-sale, Amortized Cost	1,680,491
Due within one year, Fair Value	14,239
Due after one year through five years, Fair Value	302,641
Due after five years through ten years, Fair Value	480,244
Due after ten years, Fair Value	861,907
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	5,284
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	5,080
Total investment securities available-for-sale, Fair Value	$ 1,664,111