Dividends and Share Repurchases (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		4 Months Ended	12 Months Ended
	Mar. 18, 2016	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Dec. 31, 2015
Dividends and Share Repurchases
Cash dividends paid	$ 700	$ 696	$ 700
Cash dividend (in dollars per share)	$ 0.125
Dividends payable date of record	Feb. 26, 2016
Share repurchase program amount authorized					$ 10,000
Shares repurchased (in shares)					50,068
Weighted average price per share (in dollars per share)					$ 53.52
Shares paid for tax withholding for share-based compensation				53,154
Weighted average per share prices for shares used to pay tax withholding liability (in dollars per share)				$ 53.59