Interest Rate Swaps (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Weighted average pay rate on interest-rate swaps	4.34%	4.25%	4.26%
Weighted average receive rate on interest-rate swaps	3.04%	2.70%	2.67%
Weighted average maturity (years)	4 years 9 months 18 days	4 years 1 month 6 days	5 years 10 months 24 days
Fair value of combined interest-rate swaps	$ 685	$ 789	$ 638
Interest rate swaps
Derivative [Line Items]
Notional amounts	$ 34,360	$ 30,763	$ 31,459