Guarantor Subsidiaries (Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2013
Proceeds from Sale of Property, Plant, and Equipment	$ 36	$ 0
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	125,474	134,740
Net cash provided by operating activities - discontinued operations	10,059	30,458
Total cash (used in)/provided by operating activities	135,533	165,198
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(26,296)	(34,410)
Purchases of capitalized data and other intangible assets	(16,533)	(18,928)
Cash paid for acquisitions, net of cash acquired	(670,036)	(6,852)
Purchases of investments	0	(2,351)
Change in restricted cash	(494)	2,093
Net cash used in investing activities - continuing operations	(713,323)	(58,185)
Net cash used in investing activities - discontinued operations	0	(253)
Total cash used in investing activities	(713,323)	(58,438)
Cash Received From Sale Of Subsidiary	0	2,263
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	690,017	551
Payments of Debt Issuance Costs	(14,042)	0
Repayments of long-term debt	(56,550)	(4,423)
Share repurchased and retired	(32,041)	(75,676)
Proceeds from issuance of stock related to stock options and employee benefit plans	4,440	7,119
Minimum tax withholding paid on behalf of employees for restricted stock units	(15,034)	(6,680)
Excess tax benefit related to stock options	6,275	2,652
Net cash used in financing activities - continuing operations	583,065	(76,457)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	583,065	(76,457)
Effect of exchange rate on cash	903	(2,574)
Net (decrease)/increase in cash and cash equivalents	6,178	27,729
Cash and cash equivalents at beginning of period	134,741	151,986
Less: Change in cash and cash equivalents - discontinued operations	(10,059)	(30,205)
Plus: Cash swept from discontinued operations	10,049	28,471
Cash and cash equivalents at end of period	140,909	177,981
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	(6,398)	(5,144)
Net cash provided by operating activities - discontinued operations	0	0
Total cash (used in)/provided by operating activities	(6,398)	(5,144)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(1,166)	(2,698)
Purchases of capitalized data and other intangible assets	0	(376)
Cash paid for acquisitions, net of cash acquired	0	0
Purchases of investments		0
Change in restricted cash	(700)	(4)
Net cash used in investing activities - continuing operations	(1,866)	(3,078)
Net cash used in investing activities - discontinued operations	0	0
Total cash used in investing activities	(1,866)	(3,078)
Cash Received From Sale Of Subsidiary		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	(51,892)	(4,375)
Share repurchased and retired	(32,041)	(75,676)
Proceeds from issuance of stock related to stock options and employee benefit plans	4,440	7,119
Minimum tax withholding paid on behalf of employees for restricted stock units	(15,034)	(6,680)
Excess tax benefit related to stock options	6,275	2,326
Intercompany Payments	(665,031)	0
Other	76,617	96,508
Net cash used in financing activities - continuing operations	(691)	19,222
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	(691)	19,222
Effect of exchange rate on cash	0	0
Net (decrease)/increase in cash and cash equivalents	(8,955)	11,000
Cash and cash equivalents at beginning of period	104,632	111,305	150,776
Less: Change in cash and cash equivalents - discontinued operations	0	0
Plus: Cash swept from discontinued operations	10,049	28,471
Cash and cash equivalents at end of period	105,726		150,776
Guarantor Subsidiaries [Member]
Proceeds from Sale of Property, Plant, and Equipment	36
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	113,674	134,531
Net cash provided by operating activities - discontinued operations	10,059	30,458
Total cash (used in)/provided by operating activities	123,733	164,989
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(19,415)	(27,737)
Purchases of capitalized data and other intangible assets	(14,327)	(16,432)
Cash paid for acquisitions, net of cash acquired	(640,918)	(6,852)
Purchases of investments		(2,351)
Change in restricted cash	307	0
Net cash used in investing activities - continuing operations	(674,317)	(51,109)
Net cash used in investing activities - discontinued operations	0	(253)
Total cash used in investing activities	(674,317)	(51,362)
Cash Received From Sale Of Subsidiary		2,263
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	0	551
Payments of Debt Issuance Costs	0
Repayments of long-term debt	(4,658)	(48)
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	326
Intercompany Payments	(76,617)	(90,140)
Other	647,248	0
Net cash used in financing activities - continuing operations	565,973	(89,311)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	565,973	(89,311)
Effect of exchange rate on cash	0
Net (decrease)/increase in cash and cash equivalents	15,389	24,316
Cash and cash equivalents at beginning of period	0	5,889	0
Less: Change in cash and cash equivalents - discontinued operations	10,059	(30,205)
Plus: Cash swept from discontinued operations	0	0
Cash and cash equivalents at end of period	5,330		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	18,198	5,353
Net cash provided by operating activities - discontinued operations	0	0
Total cash (used in)/provided by operating activities	18,198	5,353
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(5,715)	(3,975)
Purchases of capitalized data and other intangible assets	(2,206)	(2,120)
Cash paid for acquisitions, net of cash acquired	(29,118)	0
Purchases of investments		0
Change in restricted cash	(101)	2,097
Net cash used in investing activities - continuing operations	(37,140)	(3,998)
Net cash used in investing activities - discontinued operations	0	0
Total cash used in investing activities	(37,140)	(3,998)
Cash Received From Sale Of Subsidiary		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	(6,368)
Other	17,783	0
Net cash used in financing activities - continuing operations	17,783	(6,368)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	17,783	(6,368)
Effect of exchange rate on cash	903	(2,574)
Net (decrease)/increase in cash and cash equivalents	(256)	(7,587)
Cash and cash equivalents at beginning of period	30,109	34,792	27,205
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	29,853		27,205
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
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	588,414	96,508
Other	(588,414)	(96,508)
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
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	36
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	125,474	134,740
Net cash provided by operating activities - discontinued operations	10,059	30,458
Total cash (used in)/provided by operating activities	135,533	165,198
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(26,296)	(34,410)
Purchases of capitalized data and other intangible assets	(16,533)	(18,928)
Cash paid for acquisitions, net of cash acquired	(670,036)	(6,852)
Purchases of investments		(2,351)
Change in restricted cash	(494)	2,093
Net cash used in investing activities - continuing operations	(713,323)	(58,185)
Net cash used in investing activities - discontinued operations	0	(253)
Total cash used in investing activities	(713,323)	(58,438)
Cash Received From Sale Of Subsidiary		2,263
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		551
Repayments of long-term debt	(56,550)	(4,423)
Share repurchased and retired	(32,041)	(75,676)
Proceeds from issuance of stock related to stock options and employee benefit plans	4,440	7,119
Minimum tax withholding paid on behalf of employees for restricted stock units	(15,034)	(6,680)
Excess tax benefit related to stock options	6,275	2,652
Intercompany Payments	153,234	0
Other	153,234	0
Net cash used in financing activities - continuing operations	583,065	(76,457)
Net cash provided by financing activities - discontinued operations	0	0
Total cash (used in)/provided by financing activities	583,065	(76,457)
Effect of exchange rate on cash	903
Net (decrease)/increase in cash and cash equivalents	6,178	27,729
Cash and cash equivalents at beginning of period	134,741	151,986	177,981
Less: Change in cash and cash equivalents - discontinued operations	10,059	30,205
Plus: Cash swept from discontinued operations	10,049
Cash and cash equivalents at end of period	$ 140,909		$ 177,981