Goodwill and Intangible Assets Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Gross Carrying Value [Abstract]
Goodwill not subject to amortization (effective 1/1/02)	$ 43,528	$ 29,513
Total Goodwill And Intangible Assets, Gross Carrying Value	63,649	43,418
Goodwill and Intangible Assets Accumulated Amortization [Abstract]
Goodwill not subject to amortization (effective 1/1/02)	3,760	3,760
Total Goodwill and Intangible Assets, Accumulated Amortization	16,287	15,821
Intangibles from branch acquisition
Goodwill and Intangible Assets Gross Carrying Value [Abstract]
Finite-Lived Intangible Assets, Gross	3,015	3,015
Goodwill and Intangible Assets Accumulated Amortization [Abstract]
Finite-Lived Intangible Assets, Accumulated Amortization	3,015	3,015
Core deposit intangibles
Goodwill and Intangible Assets Gross Carrying Value [Abstract]
Finite-Lived Intangible Assets, Gross	15,202	8,986
Goodwill and Intangible Assets Accumulated Amortization [Abstract]
Finite-Lived Intangible Assets, Accumulated Amortization	7,608	7,142
Other Intangibles
Goodwill and Intangible Assets Gross Carrying Value [Abstract]
Finite-Lived Intangible Assets, Gross	1,904	1,904
Goodwill and Intangible Assets Accumulated Amortization [Abstract]
Finite-Lived Intangible Assets, Accumulated Amortization	$ 1,904	$ 1,904