COMMITMENTS AND CONTINGENCIES (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2012 sqft	Dec. 31, 2011	Dec. 31, 2010
COMMITMENTS AND CONTINGENCIES
Area of lease (in square feet)	1,900,000
Obligation for payments under leases
2013	$ 64,639,000
2014	56,397,000
2015	52,927,000
2016	15,956,000
2017	11,369,000
Thereafter	27,816,000
Total obligations under operating leases and equipment purchases	229,104,000
Rent expense
Rent expense	$ 57,400,000	$ 57,400,000	$ 33,300,000