Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands				9 Months Ended
	Sep. 18, 2015	Jun. 19, 2015	Mar. 19, 2015	Sep. 30, 2015	Sep. 30, 2014
Dividends
Cash dividends paid	$ 700	$ 700	$ 700	$ 2,099	$ 2,092
Cash dividend (in dollars per share)	$ 0.125	$ 0.125	$ 0.125
Dividends payable date of record	Aug. 28, 2015	May 29, 2015	Feb. 27, 2015