Stock Repurchase Program (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 29, 2016	Jan. 31, 2014	Dec. 31, 2013	Jul. 31, 2012
Class of Stock [Line Items]
Number of shares authorized to be repurchased (up to) (in shares)						1,000,000	500,000		1,000,000
Remaining number of shares authorized to be repurchased (in shares)	363,000			56,000				29,000
Treasury Stock
Class of Stock [Line Items]
Shares repurchase and retired during period (in shares)	64,000	383,000	246,000	212,000	261,000
Stock repurchased during period, value	$ 582	$ 3,000	$ 2,000	$ 1,700	$ 5,900