Deposits (Schedule of Maturities of Time Certificates of Deposit) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deposits [Abstract]
Due within one year	$ 2,803,509	$ 2,851,153
Due in one to two years	1,173,688	846,107
Due in two to three years	151,283	148,199
Due in three to four years	87,509	85,169
Due in four to five years	58,181	73,440
Due after five years	733	609
Total time certificates of deposit	$ 4,274,903	$ 4,004,677