Loans (Schedule of Acquired Impaired Loans, Accretable Yield and Carrying Amount) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Covered impaired loan
Accretable Yield
Balance at beginning of period	$ 37,511	$ 67,282
Accretion	(5,567)	(12,616)
Net reclassifications from nonaccretable to accretable	(56)	6,057
Disposals	(2,021)	2,280
Balance at end of period	29,867	63,003
Carrying Amount of Loans
Balance at beginning of period	232,452	403,692
Accretion	5,567	12,616
Payments received, net	(38,794)	(51,820)
Balance at end of period	199,225	364,488
Acquired Impaired Loans
Accretable Yield
Balance at beginning of period	119,450	136,646
Accretion	(11,218)	11,741
Net reclassifications from nonaccretable to accretable	12,995	19,514
Disposals	(2,471)	2,135
Balance at end of period	118,756	142,284
Carrying Amount of Loans
Balance at beginning of period	423,209	601,000
Accretion	11,218	11,741
Payments received, net	(46,114)	55,542
Balance at end of period	$ 388,313	$ 557,199