Goodwill and Other Intangible Assets - Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Goodwill
Gross Carrying Amount	$ 62,960		$ 62,960		$ 62,960
Accumulated Amortization	(43,578)		(43,578)		(40,487)
Total	19,382		19,382		22,473
Intangible amortization expense	990	$ 1,196	3,091	$ 3,588
Identifiable customer intangibles
Goodwill
Gross Carrying Amount	55,744		55,744		55,744
Accumulated Amortization	(37,374)		(37,374)		(34,972)
Total	18,370		18,370		20,772
Core deposit intangible assets
Goodwill
Gross Carrying Amount	7,216		7,216		7,216
Accumulated Amortization	(6,204)		(6,204)		(5,515)
Total	$ 1,012		$ 1,012		$ 1,701