Guarantor Subsidiaries (Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by (used in) operating activities, continuing operations	$ 183,067	$ 35,904
Net cash provided by operating activities - discontinued operations	(9,490)	(5,557)
Total cash provided by (used in) operating activities	192,557	41,461
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of redeemable noncontrolling interests	0	(72,000)
Purchases of property and equipment	(24,939)	(22,674)
Purchases of capitalized data and other intangible assets	(15,397)	(13,158)
Cash paid for acquisitions, net of cash acquired		(184,220)
Purchases of investments	0	(28,721)
Proceeds from sale of property and equipment	1,832	0
Change in restricted cash	123	0
Net cash used in investing activities - continuing operations	(38,381)	(266,926)
Net cash provided by investing activities - discontinued operations	(4,745)	(2,999)
Total cash used in investing activities	(43,126)	(269,925)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	0	857,646
Debt issuance costs	0	(21,636)
Repayments of long-term debt	(113,825)	(704,619)
Share repurchases	(28,744)	(176,512)
Proceeds from issuance of stock related to stock options and employee benefit plans	768	3,420
Cash settlement of share-based compensation	(2,577)	(1,844)
Distribution to noncontrolling interests	(10)	(4,615)
Tax benefit related to stock options	109	367
Net cash provided by/(used in) financing activities - continuing operations	(144,279)	(47,793)
Net cash provided by financing activities - discontinued operations	2	0
Total cash provided by/(used in) financing activities	(144,277)	(47,793)
Net increase/(decrease) in cash and cash equivalents	5,154	(276,257)
Cash and cash equivalents at beginning of period	259,266	426,212
Change in cash and cash equivalents - discontinued operations	4,747	2,558
Cash and cash equivalents at end of period	259,673	147,397
Parent [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by (used in) operating activities, continuing operations	3,463	(45,325)
Net cash provided by operating activities - discontinued operations	0	0
Total cash provided by (used in) operating activities	3,463	(45,325)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of redeemable noncontrolling interests		(72,000)
Purchases of property and equipment	(244)	(296)
Purchases of capitalized data and other intangible assets	0	0
Cash paid for acquisitions, net of cash acquired		(184,593)
Purchases of investments		0
Proceeds from sale of property and equipment	0	0
Change in restricted cash	0
Net cash used in investing activities - continuing operations	(244)	(256,889)
Net cash provided by investing activities - discontinued operations	0	0
Total cash used in investing activities	(244)	(256,889)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		750,000
Debt issuance costs		(21,636)
Repayments of long-term debt	(103,018)	(549,990)
Share repurchases	(28,744)	(176,512)
Proceeds from issuance of stock related to stock options and employee benefit plans	768	1,576
Cash settlement of share-based compensation	(2,577)
Distribution to noncontrolling interests	(10)	(4,615)
Tax benefit related to stock options	109	217
Other	146,483	23,840
Net cash provided by/(used in) financing activities - continuing operations	13,011	22,880
Net cash provided by financing activities - discontinued operations	0	0
Total cash provided by/(used in) financing activities	13,011	22,880
Net increase/(decrease) in cash and cash equivalents	16,230	(279,334)
Cash and cash equivalents at beginning of period	229,871	355,974
Change in cash and cash equivalents - discontinued operations	0	0
Cash and cash equivalents at end of period	246,101	76,640
Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by (used in) operating activities, continuing operations	180,827	66,832
Net cash provided by operating activities - discontinued operations	9,490	5,557
Total cash provided by (used in) operating activities	190,317	72,389
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of redeemable noncontrolling interests		0
Purchases of property and equipment	(18,146)	(18,954)
Purchases of capitalized data and other intangible assets	(14,043)	(13,117)
Cash paid for acquisitions, net of cash acquired		0
Purchases of investments		(28,721)
Proceeds from sale of property and equipment	1,832	53,847
Change in restricted cash	(184)
Net cash used in investing activities - continuing operations	(30,541)	(6,945)
Net cash provided by investing activities - discontinued operations	(4,745)	(2,999)
Total cash used in investing activities	(35,286)	(9,944)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		54,035
Debt issuance costs		0
Repayments of long-term debt	(10,726)	(104,213)
Share repurchases	0	0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	1,844
Cash settlement of share-based compensation	0
Distribution to noncontrolling interests	0	0
Tax benefit related to stock options	0	150
Other	(151,145)	(2,851)
Net cash provided by/(used in) financing activities - continuing operations	(161,871)	(51,035)
Net cash provided by financing activities - discontinued operations	2	0
Total cash provided by/(used in) financing activities	(161,869)	(51,035)
Net increase/(decrease) in cash and cash equivalents	(6,838)	11,410
Cash and cash equivalents at beginning of period	9,106	23,013
Change in cash and cash equivalents - discontinued operations	4,747	2,558
Cash and cash equivalents at end of period	(2,479)	31,865
Non-Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by (used in) operating activities, continuing operations	(1,223)	14,397
Net cash provided by operating activities - discontinued operations	0	0
Total cash provided by (used in) operating activities	(1,223)	14,397
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of redeemable noncontrolling interests		0
Purchases of property and equipment	(6,549)	(3,424)
Purchases of capitalized data and other intangible assets	(1,354)	(41)
Cash paid for acquisitions, net of cash acquired		373
Purchases of investments		0
Proceeds from sale of property and equipment	0	0
Change in restricted cash	307
Net cash used in investing activities - continuing operations	(7,596)	(3,092)
Net cash provided by investing activities - discontinued operations	0	0
Total cash used in investing activities	(7,596)	(3,092)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		53,611
Debt issuance costs		0
Repayments of long-term debt	(81)	(50,416)
Share repurchases	0	0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	0
Cash settlement of share-based compensation	0
Distribution to noncontrolling interests	0	0
Tax benefit related to stock options	0	0
Other	4,662	(20,989)
Net cash provided by/(used in) financing activities - continuing operations	4,581	(17,794)
Net cash provided by financing activities - discontinued operations	0	0
Total cash provided by/(used in) financing activities	4,581	(17,794)
Net increase/(decrease) in cash and cash equivalents	(4,238)	(6,489)
Cash and cash equivalents at beginning of period	20,289	47,225
Change in cash and cash equivalents - discontinued operations	0	0
Cash and cash equivalents at end of period	16,051	40,736
Consolidation, Eliminations [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by (used in) operating activities, continuing operations	0	0
Net cash provided by operating activities - discontinued operations	0	0
Total cash provided by (used in) operating activities	0	0
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of redeemable noncontrolling interests		0
Purchases of property and equipment	0	0
Purchases of capitalized data and other intangible assets	0	0
Cash paid for acquisitions, net of cash acquired		0
Purchases of investments		0
Proceeds from sale of property and equipment	0	0
Change in restricted cash	0
Net cash used in investing activities - continuing operations	0	0
Net cash provided by investing activities - discontinued operations	0	0
Total cash used in investing activities	0	0
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		0
Debt issuance costs		0
Repayments of long-term debt	0	0
Share repurchases	0	0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	0
Cash settlement of share-based compensation	0
Distribution to noncontrolling interests	0	0
Tax benefit related to stock options	0	0
Other	0	0
Net cash provided by/(used in) financing activities - continuing operations	0	0
Net cash provided by financing activities - discontinued operations	0	0
Total cash provided by/(used in) financing activities	0	0
Net increase/(decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Change in cash and cash equivalents - discontinued operations	0	0
Cash and cash equivalents at end of period	0	0
Total [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash provided by (used in) operating activities, continuing operations	183,067	35,904
Net cash provided by operating activities - discontinued operations	9,490	5,557
Total cash provided by (used in) operating activities	192,557	41,461
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of redeemable noncontrolling interests		(72,000)
Purchases of property and equipment	(24,939)	(22,674)
Purchases of capitalized data and other intangible assets	(15,397)	(13,158)
Cash paid for acquisitions, net of cash acquired		(184,220)
Purchases of investments		(28,721)
Proceeds from sale of property and equipment	1,832	53,847
Change in restricted cash	123
Net cash used in investing activities - continuing operations	(38,381)	(266,926)
Net cash provided by investing activities - discontinued operations	(4,745)	(2,999)
Total cash used in investing activities	(43,126)	(269,925)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		857,646
Debt issuance costs		(21,636)
Repayments of long-term debt	(113,825)	(704,619)
Share repurchases	(28,744)	(176,512)
Proceeds from issuance of stock related to stock options and employee benefit plans	768	3,420
Cash settlement of share-based compensation	(2,577)
Distribution to noncontrolling interests	(10)	(4,615)
Tax benefit related to stock options	109	367
Other	0	0
Net cash provided by/(used in) financing activities - continuing operations	(144,279)	(45,949)
Net cash provided by financing activities - discontinued operations	2	0
Total cash provided by/(used in) financing activities	(144,277)	(45,949)
Net increase/(decrease) in cash and cash equivalents	5,154	(274,413)
Cash and cash equivalents at beginning of period	259,266	426,212
Change in cash and cash equivalents - discontinued operations	4,747	2,558
Cash and cash equivalents at end of period	$ 259,673	$ 149,241