Interest-Rate Swaps (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Weighted average pay rate on interest-rate swaps	4.27%	4.25%
Weighted average receive rate on interest-rate swaps	2.80%	2.70%
Weighted average maturity (years)	3 years 10 months 24 days	4 years 1 month 6 days
Fair value of combined interest-rate swaps	$ 1,901	$ 789
Interest rate swaps
Derivative [Line Items]
Notional amounts	$ 33,525	$ 30,763