Goodwill, Core Deposit Premium and Other Intangible Assets (Changes in capitalized mortgage servicing rights) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period			$ 15,653	$ 11,276
Originations			10,595	7,916
Amortization			(5,548)	(4,727)
Valuation adjustment	0	(493)	496	(674)
Balance at end of period	$ 21,196	$ 13,791	$ 21,196	$ 13,791