Goodwill and Intangible Assets Mortgage Servicing Rights (Details) - USD ($)		3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 08, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets		$ (545,000)	$ (455,000)	$ (1,651,000)	$ (1,312,000)
Mortgage Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 1,069,000			0		$ 1,069,000
Capitalization Of Mortgage Servicing Rights				0		14,000
Amortization of Intangible Assets		(33,000)	$ (14,000)	(105,000)	$ (14,000)	(98,000)
Finite-Lived Intangible Assets, Net		$ 880,000		$ 880,000		$ 985,000	$ 0