Securities (Securities available for sale (debt maturities)) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Amortized Cost
Due in 1 year or less	$ 1,645
Due in 1 to 5 years	15,892
Due in 5 to 10 years	87,334
Due after 10 years	212,770
Total debt securities	317,641
Mortgage-backed securities	1,226,085
Equity securities	13,158
Amortized Cost	1,556,884	$ 1,584,703
Estimated Fair Value
Due in 1 year or less	1,653
Due in 1 to 5 years	16,181
Due in 5 to 10 years	90,004
Due after 10 years	224,515
Total debt securities	332,353
Mortgage-backed securities	1,220,732
Equity securities	13,507
Estimated Fair Value	$ 1,566,592	$ 1,578,434