INCOME TAXES - Summary of temporary differences between financial statement carrying amounts and tax bases of assets and liabilities that give rise to significant portions of deferred taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current deferred income tax assets:
Provision for doubtful accounts	$ 2,457	$ 3,691
Accrued compensation	1,745	1,251
Other accrued expenses	5	45
Deferred revenue	1,097	758
Restructuring liability	953	1,029
Other	165	116
Current deferred income tax assets	6,422	6,890
Less: valuation allowance	(6,422)	(6,890)
Net current deferred income tax assets
Long-term deferred income tax assets:
Property and equipment	38,340	36,093
Goodwill	4,323	4,790
Intangible assets	(4,495)	(2,605)
Deferred revenue, less current portion	909	779
Restructuring liability, less current portion	1,279	1,856
Deferred rent	5,777	6,304
Stock-based compensation	2,387	1,660
U.S. net operating loss carryforwards	62,313	60,972
Foreign net operating loss carryforwards, less current portion	3,755	3,650
Capital loss carryforwards	2,271	2,271
Tax credit carryforwards	980	968
Other	2,081	1,881
Long-term deferred income tax assets	119,920	118,619
Less: valuation allowance	(118,011)	(116,523)
Net long-term deferred income tax assets	1,909	2,096
Net deferred tax assets	$ 1,909	$ 2,096