SUBSEQUENT EVENT (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended							12 Months Ended			0 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 30, 2015	Jan. 07, 2015
SUBSEQUENT EVENT
Quarterly dividend declared (in dollars per share)	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.72	$ 0.54
Dividend paid in cash								$ 15,532	$ 9,978	$ 16,432
Subsequent event
SUBSEQUENT EVENT
Quarterly dividend declared (in dollars per share)												$ 0.18
Dividend paid in cash											$ 3,900