Affordable Housing Tax Credit Limited Partnership (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Affordable housing tax credit investment	$ 5,000		$ 3,000
Less amortization	400		231
Net affordable housing tax credit investment	4,600		2,769
Unfunded commitment	$ 3,522		$ 2,257
Funding period for unfunded commitment (in years)	10 years
Tax credits and other tax benefits recognized	$ 168	$ 119
Tax credit amortization expense included in provision for income taxes	$ 169	$ 126