Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (81,304)	$ 139,022
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Goodwill and asset impairment	85,661	2,676
Loss on pending sale of student receivables	930
Depreciation and amortization expense	60,555	63,319
Bad debt expense	28,967	40,909
Compensation expense related to share-based awards	7,302	11,884
Loss (gain) on disposition of property and equipment	293	(1,794)
Changes in operating assets and liabilities	(69,910)	(46,599)
Net cash provided by operating activities	32,494	209,417
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of available-for-sale investments	(117,188)	(149,234)
Sales of available-for-sale investments	146,873	148,934
Purchases of property and equipment	(29,496)	(67,444)
Proceeds on the sale of assets		6,259
Business acquisition, net of acquired cash	(3,094)
Other	(1,533)	40
Net cash used in investing activities	(4,438)	(61,445)
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of treasury stock	(56,431)	(137,033)
Issuance of common stock	1,262	3,827
Tax benefit associated with stock option exercises		377
Payments of assumed loans upon business acquisition	(318)
Payments of contingent consideration	(5,818)	(12,589)
Payments of capital lease obligations	(741)	(855)
Net cash used in financing activities	(62,046)	(146,273)
EFFECT OF FOREIGN CURRENCY EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS:	(3,774)	(2,080)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(37,764)	(381)
DISCONTINUED OPERATIONS CASH ACTIVITY INCLUDED ABOVE:
Add: Cash balance of discontinued operations, beginning of the period		28,838
Less: Cash balance of discontinued operations, end of the period		36,428
CASH AND CASH EQUIVALENTS, beginning of the period	280,592	260,644
CASH AND CASH EQUIVALENTS, end of the period	$ 242,828	$ 252,673