Loans (Changes in the carrying amount and accretable yield for acquired impaired loans) (Details) - Acquired Impaired Loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accretable Yield
Balance at the beginning of the period, Accretable Yield	$ 119,450	$ 136,646
Accretable Yield, Accretion	(40,756)	(49,271)
Net reclassifications from nonaccretable to accretable, Accretable Yield	37,245	45,824
Disposals, Accretable Yield	(26,116)	(13,749)
Balance at the end of the period, Accretable Yield	89,823	119,450
Carrying Amount of Loans
Balance at the beginning of the period, Carrying Amount of Loans	423,209	601,000
Accretion, Carrying Amount of Loans	40,756	49,271
Payments received, net, Carrying Amount of Loans	(179,256)	(227,062)
Balance at the end of the period, Carrying Amount of Loans	$ 284,709	$ 423,209