Condensed Consolidating Financial Statements (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
CONDENSED, CONSOLIDATING STATEMENTS OF CASH FLOWS
Net cash provided by operating activities	$ 2,579	$ 149,096	$ 12,215	$ 145,632
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of available-for-sale investments (substantially restricted)	8,447	14,281	19,267	31,743
Proceeds from settlement of investments (substantially restricted)		19,221		19,221
Purchases of short-term investments (substantially restricted)	(112,733)	(111,259)	(324,489)	(316,700)
Proceeds from maturities of short-term investments (substantially restricted)	113,525	5,316	323,638	205,816
Purchases of property and equipment	(11,663)	(15,217)	(30,295)	(24,190)
Proceeds from disposal of assets and businesses	219		391
Cash paid for acquisitions, net of cash acquired		(53)		(53)
Net cash used in investing activities	(2,205)	(87,711)	(11,488)	(84,163)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt		389,025		389,025
Transaction costs for issuance and amendment of debt		(17,062)		(17,062)
Payments on debt	(375)	(191,250)	(750)	(191,250)
Additional consideration issued in connection with conversion of mezzanine equity		(218,333)		(218,333)
Transaction costs for the conversion and issuance of stock		(3,469)		(3,736)
Cash dividends paid on mezzanine equity		(20,477)		(20,477)
Proceeds from exercise of stock options	1	181	23	364
Net cash used in financing activities	(374)	(61,385)	(727)	(61,469)
NET CHANGE IN CASH AND CASH EQUIVALENTS
CASH AND CASH EQUIVALENTS - Beginning of period
CASH AND CASH EQUIVALENTS - End of period
Parent [Member]
CONDENSED, CONSOLIDATING STATEMENTS OF CASH FLOWS
Net cash provided by operating activities	13,406	3,391	23,493	675
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital contribution from subsidiary guarantors/Dividends to parent		241,315		241,315
Net cash used in investing activities		241,315		241,315
CASH FLOWS FROM FINANCING ACTIVITIES:
Additional consideration issued in connection with conversion of mezzanine equity		(218,333)		(218,333)
Transaction costs for the conversion and issuance of stock		(3,469)		(3,736)
Cash dividends paid on mezzanine equity		(20,477)		(20,477)
Proceeds from exercise of stock options	1	181	23	364
Intercompany financings	(13,407)	(2,608)	(23,516)	192
Net cash used in financing activities	(13,406)	(244,706)	(23,493)	(241,990)
NET CHANGE IN CASH AND CASH EQUIVALENTS
CASH AND CASH EQUIVALENTS - Beginning of period
CASH AND CASH EQUIVALENTS - End of period
Subsidiary Guarantors [Member]
CONDENSED, CONSOLIDATING STATEMENTS OF CASH FLOWS
Net cash provided by operating activities	(10,339)	135,816	(15,573)	119,737
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of available-for-sale investments (substantially restricted)	8,447	14,281	19,267	31,743
Proceeds from settlement of investments (substantially restricted)		19,221		19,221
Purchases of short-term investments (substantially restricted)	(100,000)	(100,000)	(300,000)	(294,142)
Proceeds from maturities of short-term investments (substantially restricted)	100,000		300,000	200,500
Purchases of property and equipment	(8,986)	(9,898)	(23,811)	(14,157)
Proceeds from disposal of assets and businesses	219		391
Capital contribution from subsidiary guarantors/Dividends to parent	(2,373)	(1,426)	(3,040)	(2,108)
Net cash used in investing activities	(2,693)	(77,822)	(7,193)	(58,943)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt		389,025		389,025
Transaction costs for issuance and amendment of debt		(17,062)		(17,062)
Payments on debt	(375)	(191,250)	(750)	(191,250)
Intercompany financings	13,407	2,608	23,516	(192)
Capital contribution to non-guarantors/Dividend from subsidiary guarantors		(241,315)		(241,315)
Net cash used in financing activities	13,032	(57,994)	22,766	(60,794)
NET CHANGE IN CASH AND CASH EQUIVALENTS
CASH AND CASH EQUIVALENTS - Beginning of period
CASH AND CASH EQUIVALENTS - End of period
Non-Guarantors [Member]
CONDENSED, CONSOLIDATING STATEMENTS OF CASH FLOWS
Net cash provided by operating activities	(488)	9,889	4,295	25,220
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of short-term investments (substantially restricted)	(12,733)	(11,259)	(24,489)	(22,558)
Proceeds from maturities of short-term investments (substantially restricted)	13,525	5,316	23,638	5,316
Purchases of property and equipment	(2,677)	(5,319)	(6,484)	(10,033)
Cash paid for acquisitions, net of cash acquired		(53)		(53)
Net cash used in investing activities	(1,885)	(11,315)	(7,335)	(27,328)
CASH FLOWS FROM FINANCING ACTIVITIES:
Capital contribution to non-guarantors/Dividend from subsidiary guarantors	2,373	1,426	3,040	2,108
Net cash used in financing activities	2,373	1,426	3,040	2,108
NET CHANGE IN CASH AND CASH EQUIVALENTS
CASH AND CASH EQUIVALENTS - Beginning of period
CASH AND CASH EQUIVALENTS - End of period
Eliminations [Member]
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital contribution from subsidiary guarantors/Dividends to parent	2,373	(239,889)	3,040	(239,207)
Net cash used in investing activities	2,373	(239,889)	3,040	(239,207)
CASH FLOWS FROM FINANCING ACTIVITIES:
Capital contribution to non-guarantors/Dividend from subsidiary guarantors	(2,373)	239,889	(3,040)	239,207
Net cash used in financing activities	(2,373)	239,889	(3,040)	239,207
NET CHANGE IN CASH AND CASH EQUIVALENTS
CASH AND CASH EQUIVALENTS - Beginning of period
CASH AND CASH EQUIVALENTS - End of period