Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 52,076	$ 73,035
Adjustments to reconcile net income to net cash provided by operating activities:
Goodwill and asset impairment	83
Depreciation and amortization expense	20,106	20,366
Bad debt expense	9,390	17,151
Compensation expense related to share-based awards	2,780	4,200
Loss (gain) on disposition of property and equipment	32	(1,801)
Changes in operating assets and liabilities	(67,115)	(53,295)
Net cash provided by operating activities	17,352	59,656
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of available-for-sale investments	(40,300)	(60,934)
Sales of available-for-sale investments	40,438	60,774
Purchases of property and equipment	(12,303)	(23,792)
Earnout payments	(3,555)	(4,235)
Proceeds on the sale of assets		6,259
Other	(12)	85
Net cash used in investing activities	(15,732)	(21,843)
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of treasury stock	(56,431)	(89,915)
Issuance of common stock	477	1,292
Tax benefit associated with stock option exercises		159
Payments of capital lease obligations	(547)	(641)
Net cash used in financing activities	(56,501)	(89,105)
EFFECT OF FOREIGN CURRENCY EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS:	3,677	1,071
NET DECREASE IN CASH AND CASH EQUIVALENTS	(51,204)	(50,221)
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		25,136
CASH AND CASH EQUIVALENTS, beginning of the period	280,592	260,644
CASH AND CASH EQUIVALENTS, end of the period	$ 229,388	$ 214,125