Guarantor Subsidiaries (Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2013
Proceeds from Sale of Property, Plant, and Equipment	$ 13,937	$ 0
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	210,743	237,521
Net cash provided by operating activities - discontinued operations	(2,104)	23,569
Total cash (used in)/provided by operating activities	208,639	261,090
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(37,122)	(51,667)
Purchases of capitalized data and other intangible assets	(25,207)	(28,795)
Cash paid for acquisitions, net of cash acquired	(672,336)	(70,904)
Purchases of investments	0	(2,351)
Change in restricted cash	(1,443)	5,728
Net cash used in investing activities - continuing operations	(696,646)	(145,726)
Net cash used in investing activities - discontinued operations	1,536	1,863
Total cash used in investing activities	(695,110)	(143,863)
Cash Received From Sale Of Subsidiary	25,525	2,263
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	690,017	1,075
Payments of Debt Issuance Costs	(14,042)	0
Repayments of long-term debt	(118,836)	(4,516)
Share repurchased and retired	(72,781)	(133,565)
Proceeds from issuance of stock related to stock options and employee benefit plans	5,736	11,662
Minimum tax withholding paid on behalf of employees for restricted stock units	(15,247)	(6,893)
Excess tax benefit related to stock options	6,352	2,895
Net cash used in financing activities - continuing operations	481,199	(129,342)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	481,199	(129,342)
Effect of exchange rate on cash	(144)	(1,341)
Net (decrease)/increase in cash and cash equivalents	(5,416)	(13,456)
Cash and cash equivalents at beginning of period	134,419	149,567
Less: Change in cash and cash equivalents - discontinued operations	568	(25,432)
Plus: Cash swept from discontinued operations	(1,953)	25,788
Cash and cash equivalents at end of period	127,618	136,467
Parent [Member]
Proceeds from Sale of Property, Plant, and Equipment	0
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	(7,831)	3,304
Net cash provided by operating activities - discontinued operations	0	0
Total cash (used in)/provided by operating activities	(7,831)	3,304
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(1,430)	(6,333)
Purchases of capitalized data and other intangible assets	0	(362)
Cash paid for acquisitions, net of cash acquired	0	0
Purchases of investments		0
Change in restricted cash	(1,750)	3,678
Net cash used in investing activities - continuing operations	(3,180)	(3,017)
Net cash used in investing activities - discontinued operations	0	0
Total cash used in investing activities	(3,180)	(3,017)
Cash Received From Sale Of Subsidiary	0	0
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	690,017	0
Payments of Debt Issuance Costs	(14,042)
Repayments of long-term debt	(113,967)	(4,375)
Share repurchased and retired	(72,781)	(133,565)
Proceeds from issuance of stock related to stock options and employee benefit plans	5,736	11,662
Minimum tax withholding paid on behalf of employees for restricted stock units	(15,247)	(6,893)
Excess tax benefit related to stock options	6,352	2,895
Intercompany Payments	(665,031)	0
Other	179,187	101,583
Net cash used in financing activities - continuing operations	224	(28,693)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	224	(28,693)
Effect of exchange rate on cash	0	0
Net (decrease)/increase in cash and cash equivalents	(10,787)	(28,406)
Cash and cash equivalents at beginning of period	104,310	111,305	107,353
Less: Change in cash and cash equivalents - discontinued operations	0	0
Plus: Cash swept from discontinued operations	(3,489)	24,454
Cash and cash equivalents at end of period	90,034		107,353
Guarantor Subsidiaries [Member]
Proceeds from Sale of Property, Plant, and Equipment	13,937
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	190,961	218,562
Net cash provided by operating activities - discontinued operations	(2,104)	22,235
Total cash (used in)/provided by operating activities	188,857	240,797
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(28,016)	(39,614)
Purchases of capitalized data and other intangible assets	(22,258)	(24,725)
Cash paid for acquisitions, net of cash acquired	(643,218)	(71,446)
Purchases of investments		(2,351)
Change in restricted cash	307	0
Net cash used in investing activities - continuing operations	(653,723)	(135,873)
Net cash used in investing activities - discontinued operations	0	1,863
Total cash used in investing activities	(653,723)	(134,010)
Cash Received From Sale Of Subsidiary	25,525	2,263
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	0	1,075
Payments of Debt Issuance Costs	0
Repayments of long-term debt	(4,869)	(141)
Share repurchased and retired	0	0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	0
Minimum tax withholding paid on behalf of employees for restricted stock units	0	0
Excess tax benefit related to stock options	0	0
Intercompany Payments	(179,187)	(86,144)
Other	653,885	0
Net cash used in financing activities - continuing operations	469,829	(85,210)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	469,829	(85,210)
Effect of exchange rate on cash	0	0
Net (decrease)/increase in cash and cash equivalents	4,963	21,577
Cash and cash equivalents at beginning of period	0	2,521	0
Less: Change in cash and cash equivalents - discontinued operations	(2,104)	(24,098)
Plus: Cash swept from discontinued operations	0	0
Cash and cash equivalents at end of period	7,067		0
Non-Guarantor Subsidiaries [Member]
Proceeds from Sale of Property, Plant, and Equipment	0
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	27,613	15,655
Net cash provided by operating activities - discontinued operations	0	1,334
Total cash (used in)/provided by operating activities	27,613	16,989
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(7,676)	(5,720)
Purchases of capitalized data and other intangible assets	(2,949)	(3,708)
Cash paid for acquisitions, net of cash acquired	(29,118)	542
Purchases of investments		0
Change in restricted cash	0	2,050
Net cash used in investing activities - continuing operations	(39,743)	(6,836)
Net cash used in investing activities - discontinued operations	1,536	0
Total cash used in investing activities	(38,207)	(6,836)
Cash Received From Sale Of Subsidiary	0	0
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	0	0
Payments of Debt Issuance Costs	0
Repayments of long-term debt	0	0
Share repurchased and retired	0	0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	0
Minimum tax withholding paid on behalf of employees for restricted stock units	0	0
Excess tax benefit related to stock options	0	0
Intercompany Payments	0	(15,439)
Other	11,146	0
Net cash used in financing activities - continuing operations	11,146	(15,439)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	11,146	(15,439)
Effect of exchange rate on cash	(144)	(1,341)
Net (decrease)/increase in cash and cash equivalents	408	(6,627)
Cash and cash equivalents at beginning of period	30,109	35,741	29,114
Less: Change in cash and cash equivalents - discontinued operations	1,536	(1,334)
Plus: Cash swept from discontinued operations	1,536	1,334
Cash and cash equivalents at end of period	30,517		29,114
Consolidation, Eliminations [Member]
Proceeds from Sale of Property, Plant, and Equipment	0
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	0	0
Net cash provided by operating activities - discontinued operations	0	0
Total cash (used in)/provided by operating activities	0	0
Net Cash Provided by (Used in) Investing Activities [Abstract]
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	0
Purchases of investments		0
Change in restricted cash	0	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 investing activities	0	0
Cash Received From Sale Of Subsidiary	0	0
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	0	0
Payments of Debt Issuance Costs	0
Repayments of long-term debt	0	0
Share repurchased and retired	0	0
Proceeds from issuance of stock related to stock options and employee benefit plans	0	0
Minimum tax withholding paid on behalf of employees for restricted stock units	0	0
Excess tax benefit related to stock options	0	0
Intercompany Payments	844,218	101,583
Other	(844,218)	(101,583)
Net cash used in financing activities - continuing operations	0	0
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	0	0
Effect of exchange rate on cash	0	0
Net (decrease)/increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0	0
Less: Change in cash and cash equivalents - discontinued operations	0	0
Plus: Cash swept from discontinued operations	0	0
Cash and cash equivalents at end of period	0		0
Total [Member]
Proceeds from Sale of Property, Plant, and Equipment	13,937
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	210,743	237,521
Net cash provided by operating activities - discontinued operations	(2,104)	23,569
Total cash (used in)/provided by operating activities	208,639	261,090
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(37,122)	(51,667)
Purchases of capitalized data and other intangible assets	(25,207)	(28,795)
Cash paid for acquisitions, net of cash acquired	(672,336)	(70,904)
Purchases of investments		(2,351)
Change in restricted cash	(1,443)	5,728
Net cash used in investing activities - continuing operations	(696,646)	(145,726)
Net cash used in investing activities - discontinued operations	1,536	1,863
Total cash used in investing activities	(695,110)	(143,863)
Cash Received From Sale Of Subsidiary	25,525	2,263
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		1,075
Repayments of long-term debt	(118,836)	(4,516)
Share repurchased and retired	(72,781)	(133,565)
Proceeds from issuance of stock related to stock options and employee benefit plans	5,736	11,662
Minimum tax withholding paid on behalf of employees for restricted stock units	(15,247)	(6,893)
Excess tax benefit related to stock options	6,352	2,895
Intercompany Payments	0	0
Other	0	0
Net cash used in financing activities - continuing operations	481,199	(129,342)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	481,199	(129,342)
Effect of exchange rate on cash	(144)
Net (decrease)/increase in cash and cash equivalents	(5,416)	(13,456)
Cash and cash equivalents at beginning of period	134,419	149,567	136,467
Less: Change in cash and cash equivalents - discontinued operations	(568)	25,432
Plus: Cash swept from discontinued operations	(1,953)
Cash and cash equivalents at end of period	$ 127,618		$ 136,467