FIXED ASSETS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
FIXED ASSETS
Fixed assets, gross	$ 191,698	$ 171,777
Less: accumulated depreciation and amortization	(164,504)	(150,740)
Depreciation and amortization	14,522	16,009	16,350
Total fixed assets, net	27,194	21,037
Computer hardware and software, including internal-use software and website development
FIXED ASSETS
Fixed assets, gross	170,702	151,155
Furniture and equipment
FIXED ASSETS
Fixed assets, gross	14,457	14,283
Leasehold improvements
FIXED ASSETS
Fixed assets, gross	6,539	6,339
Equipment under capital leases
FIXED ASSETS
Fixed assets, gross	4,200	1,700
Less: accumulated depreciation and amortization	(2,100)	(1,700)
Depreciation and amortization	$ 429	$ 221