SUPPLEMENTAL CASH FLOW INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash paid for:
Interest	$ 7,630	$ 5,068	$ 2,594
Income taxes paid, net	8,843	4,712	19,898
Non-cash investing and financing transactions:
Property, equipment, and leasehold improvements accrued in accounts payable and other long-term liabilities	3,076	917	2,309
Obligations incurred in purchased transaction		29,447	15,256
Notes payable and capitalized lease obligations incurred	176	11,200	3,827
Conversion of convertible notes into common stock			27,168
Dividends payable	$ 3,231	$ 1,786