QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Quarterly financial data
Gross margin	$ 185,800	$ 193,500	$ 210,000	$ 152,200	$ 129,800	$ 140,300	$ 86,800	$ 103,500	$ 741,500	$ 460,400
Immaterial correction of an error related to an inconsistent policy related to income statement classification of shipping and handling costs | Impact of correction
Quarterly financial data
Gross margin		$ 19,100	$ 21,100	$ 10,000