Securities (Schedule of Contractual Maturities of Investment Securities Available for Sale) (Details) $ in Thousands	Jun. 30, 2015 USD ($)
Available-for-sale Securities [Abstract]
Due within one year, Amortized Cost	$ 20,112
Due after one year through five years, Amortized Cost	391,397
Due after five years through ten years, Amortized Cost	535,833
Due after ten years, Amortized Cost	954,777
No stated maturity date, Amortized Cost Basis	5,284
Total investment securities available-for-sale, Amortized Cost	1,907,403
Due within one year, Fair Value	20,399
Due after one year through five years, Fair Value	392,321
Due after five years through ten years, Fair Value	539,403
Due after ten years, Fair Value	957,174
No stated maturity date, Fair Value	5,148
Total investment securities available-for-sale, Fair Value	$ 1,914,445