Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands			6 Months Ended
	Jun. 19, 2015	Mar. 19, 2015	Jun. 30, 2015	Jun. 30, 2014
Dividends
Cash dividends paid	$ 700	$ 700	$ 1,399	$ 1,394
Cash dividend (in dollars per share)	$ 0.125	$ 0.125
Dividends payable date of record	May 29, 2015	Feb. 27, 2015