Guarantor Subsidiaries Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	$ 69,726	$ 21,520
Cash Provided by (Used in) Operating Activities, Discontinued Operations	4,694	(1,113)
Total cash provided by operating activities	65,032	22,633
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of redeemable noncontrolling interests	0	(72,000)
Purchases of property and equipment	(13,519)	(9,721)
Purchases of capitalized data and other intangible assets	(6,959)	(6,298)
Cash paid for acquisitions, net of cash acquired		(27,397)
Purchases of investments	0	(28,749)
Proceeds from sale of property and equipment	45	0
Proceeds from sale of investments	0	53,847
Change in restricted cash	(186)	0
Net cash used in investing activities - continuing operations	(20,619)	(90,318)
Net cash used in investing activities - discontinued operations	239	(1,489)
Total cash used in by investing activities	(20,380)	(91,807)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Repayment of long-term debt	(52,247)	(211,320)
Share repurchases	0	(15,082)
Proceeds from issuance of stock related to stock options and employee benefit plans	187	2,217
Distributions to noncontrolling interests	(10)	(4,290)
Tax benefit related to stock options	56	217
Net cash used in financing activities - continuing operations	(52,014)	(228,258)
Net cash provided by financing activities - discontinued operations	1	0
Total cash used in financing activities	(52,013)	(228,258)
Net increase/(decrease) in cash and cash equivalents	(7,361)	(297,432)
Cash and cash equivalents at beginning of period	259,266	426,212
Change in cash and cash equivalents - discontinued operations	(4,454)	(376)
Cash and cash equivalents at end of period	256,359	129,156
Parent [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	19,166	13,743
Cash Provided by (Used in) Operating Activities, Discontinued Operations	0	0
Total cash provided by operating activities	19,166	13,743
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of redeemable noncontrolling interests		(72,000)
Purchases of property and equipment	(989)	(51)
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	(989)	(72,051)
Net cash used in investing activities - discontinued operations	0	0
Total cash used in by investing activities	(989)	(72,051)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Repayment of long-term debt	(42,000)	(201,446)
Share repurchases		(15,082)
Proceeds from issuance of stock related to stock options and employee benefit plans	187	2,217
Distributions to noncontrolling interests	(10)	(4,290)
Tax benefit related to stock options	56	217
Other	36,181	(23,152)
Net cash used in financing activities - continuing operations	(5,586)	(241,536)
Net cash provided by financing activities - discontinued operations	0	0
Total cash used in financing activities	(5,586)	(241,536)
Net increase/(decrease) in cash and cash equivalents	12,591	(299,844)
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	242,462	56,130
Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	56,938	11,467
Cash Provided by (Used in) Operating Activities, Discontinued Operations	(4,694)	1,113
Total cash provided by operating activities	52,244	12,580
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of redeemable noncontrolling interests		0
Purchases of property and equipment	(8,762)	(8,792)
Purchases of capitalized data and other intangible assets	(6,876)	(6,298)
Cash paid for acquisitions, net of cash acquired		(27,397)
Purchases of investments		(28,749)
Proceeds from sale of property and equipment	45	53,847
Change in restricted cash	(186)
Net cash used in investing activities - continuing operations	(15,779)	(17,389)
Net cash used in investing activities - discontinued operations	239	(1,489)
Total cash used in by investing activities	(15,540)	(18,878)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Repayment of long-term debt	(10,214)	(9,871)
Share repurchases		0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	0
Distributions to noncontrolling interests	0	0
Tax benefit related to stock options	0	0
Other	(43,937)	17,514
Net cash used in financing activities - continuing operations	(54,151)	7,643
Net cash provided by financing activities - discontinued operations	1	0
Total cash used in financing activities	(54,150)	7,643
Net increase/(decrease) in cash and cash equivalents	(17,446)	1,345
Cash and cash equivalents at beginning of period	9,106	23,013
Change in cash and cash equivalents - discontinued operations	(4,454)	(376)
Cash and cash equivalents at end of period	(3,886)	24,734
Non-Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	(6,378)	(3,690)
Cash Provided by (Used in) Operating Activities, Discontinued Operations	0	0
Total cash provided by operating activities	(6,378)	(3,690)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of redeemable noncontrolling interests		0
Purchases of property and equipment	(3,768)	(878)
Purchases of capitalized data and other intangible assets	(83)	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	(3,851)	(878)
Net cash used in investing activities - discontinued operations	0	0
Total cash used in by investing activities	(3,851)	(878)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Repayment of long-term debt	(33)	(3)
Share repurchases		0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	0
Distributions to noncontrolling interests	0	0
Tax benefit related to stock options	0	0
Other	7,756	5,638
Net cash used in financing activities - continuing operations	7,723	5,635
Net cash provided by financing activities - discontinued operations	0	0
Total cash used in financing activities	7,723	5,635
Net increase/(decrease) in cash and cash equivalents	(2,506)	1,067
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	17,783	48,292
Consolidation, Eliminations [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	0	0
Cash Provided by (Used in) Operating Activities, Discontinued Operations	0	0
Total cash provided by operating activities	0	0
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase 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 used in investing activities - discontinued operations	0	0
Total cash used in by investing activities	0	0
Net Cash Provided by (Used in) Financing Activities [Abstract]
Repayment of long-term debt	0	0
Share repurchases		0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	0
Distributions to noncontrolling interests	0	0
Tax benefit related to stock options	0	0
Other	0	0
Net cash used in financing activities - continuing operations	0	0
Net cash provided by financing activities - discontinued operations	0	0
Total cash 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	69,726	21,520
Cash Provided by (Used in) Operating Activities, Discontinued Operations	(4,694)	1,113
Total cash provided by operating activities	65,032	22,633
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of redeemable noncontrolling interests		(72,000)
Purchases of property and equipment	(13,519)	(9,721)
Purchases of capitalized data and other intangible assets	(6,959)	(6,298)
Cash paid for acquisitions, net of cash acquired		(27,397)
Purchases of investments		(28,749)
Proceeds from sale of property and equipment	45	53,847
Change in restricted cash	(186)
Net cash used in investing activities - continuing operations	(20,619)	(90,318)
Net cash used in investing activities - discontinued operations	239	(1,489)
Total cash used in by investing activities	(20,380)	(91,807)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Repayment of long-term debt	(52,247)	(211,320)
Share repurchases		(15,082)
Proceeds from issuance of stock related to stock options and employee benefit plans	187	2,217
Distributions to noncontrolling interests	(10)	(4,290)
Tax benefit related to stock options	56	217
Other	0	0
Net cash used in financing activities - continuing operations	(52,014)	(228,258)
Net cash provided by financing activities - discontinued operations	1	0
Total cash used in financing activities	(52,013)	(228,258)
Net increase/(decrease) in cash and cash equivalents	(7,361)	(297,432)
Cash and cash equivalents at beginning of period	259,266	426,212
Change in cash and cash equivalents - discontinued operations	(4,454)	(376)
Cash and cash equivalents at end of period	$ 256,359	$ 129,156