Goodwill, Core Deposit Premium and Other Intangible Assets (Changes in capitalized mortgage servicing rights) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	$ 21,788	$ 15,653
Originations	1,435	3,245
Amortization	(1,079)	(1,761)
Valuation adjustment	0	496
Balance at end of period	22,144	17,633
Fair value of mortgage servicing rights	$ 32,032	$ 19,389	$ 32,000
Servicing Asset, Net to Servicing Portfolio, Percentage	0.71%	0.58%