SELLING, GENERAL AND ADMINISTRATIVE EXPENSES (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES
Compensation and benefits	$ 21,166	$ 22,327	$ 19,116
Professional services	9,864	6,658	8,026
Occupancy related costs	24,041	17,824	10,684
Amortization of intangible assets	5,030	5,291	4,891
Goodwill impairment			2,816
Depreciation and amortization	2,609	2,097	1,470
Other	12,002	7,934	10,349
Total	$ 74,712	$ 62,131	$ 57,352