Guarantor Subsidiaries (Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	$ 86,700	$ 41,244
Net cash used in operating activities - discontinued operations	27	(1,010)
Total cash provided by operating activities	86,727	40,234
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of subsidiary shares from and other decreases in noncontrolling interests	(18,023)	0
Purchases of property and equipment	(9,810)	(11,397)
Purchases of capitalized data and other intangible assets	(9,021)	(11,244)
Purchases of investments	(440)	(388)
Proceeds from sale of property and equipment	8	0
Change in restricted cash	(117)	146
Net cash used in investing activities - continuing operations	(37,403)	(22,883)
Net cash provided by investing activities - discontinued operations	0	0
Total cash used in investing activities	(37,403)	(22,883)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt	0	135
Repayments of long-term debt	(15,830)	(35,551)
Proceeds from issuance of shares in connection with share-based compensation	6,296	10,701
Minimum tax withholdings related to net share settlements	(7,178)	(11,792)
Excess tax benefit related to stock options	1,265	4,575
Intercompany Payments	0	0
Intercompany proceeds	0	0
Net cash used in financing activities - continuing operations	(15,447)	(31,932)
Net cash provided by financing activities - discontinued operations	0	0
Total cash provided by/(used in) financing activities	(15,447)	(31,932)
Effect of exchange rate on cash	137	67
Net change in cash and cash equivalents	34,014	(14,514)
Cash and cash equivalents at beginning of period	99,090	104,677
Less: Change in cash and cash equivalents - discontinued operations	27	(1,010)
Plus: Cash swept from discontinued operations	27	(1,467)
Cash and cash equivalents at end of period	133,104	89,706
Parent [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	5,031	(25,381)
Net cash used in operating activities - discontinued operations	0	0
Total cash provided by operating activities	5,031	(25,381)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of subsidiary shares from and other decreases in noncontrolling interests	0
Purchases of property and equipment	(158)	(359)
Purchases of capitalized data and other intangible assets	0	0
Purchases of investments	0	0
Proceeds from sale of property and equipment	0
Change in restricted cash	(4)	0
Net cash used in investing activities - continuing operations	(162)	(359)
Net cash provided by investing activities - discontinued operations	0	0
Total cash used in investing activities	(162)	(359)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		0
Repayments of long-term debt	(10,625)	(35,551)
Proceeds from issuance of shares in connection with share-based compensation	6,296	10,701
Minimum tax withholdings related to net share settlements	(7,178)	(11,792)
Excess tax benefit related to stock options	1,265	4,575
Intercompany Payments	(22,083)	0
Intercompany proceeds	77,797	46,566
Net cash used in financing activities - continuing operations	45,472	14,499
Net cash provided by financing activities - discontinued operations	0	0
Total cash provided by/(used in) financing activities	45,472	14,499
Effect of exchange rate on cash	0	0
Net change in cash and cash equivalents	50,341	(11,241)
Cash and cash equivalents at beginning of period	28,259	61,602
Less: Change in cash and cash equivalents - discontinued operations	0	0
Plus: Cash swept from discontinued operations	0	(1,467)
Cash and cash equivalents at end of period	78,600	48,894
Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	84,743	53,933
Net cash used in operating activities - discontinued operations	27	(1,010)
Total cash provided by operating activities	84,770	52,923
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of subsidiary shares from and other decreases in noncontrolling interests	0
Purchases of property and equipment	(7,659)	(8,511)
Purchases of capitalized data and other intangible assets	(7,601)	(7,797)
Purchases of investments	0	0
Proceeds from sale of property and equipment	8
Change in restricted cash	0	0
Net cash used in investing activities - continuing operations	(15,252)	(16,308)
Net cash provided by investing activities - discontinued operations	0	0
Total cash used in investing activities	(15,252)	(16,308)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		135
Repayments of long-term debt	(5,205)	0
Proceeds from issuance of shares in connection with share-based compensation	0	0
Minimum tax withholdings related to net share settlements	0	0
Excess tax benefit related to stock options	0	0
Intercompany Payments	(77,797)	(42,910)
Intercompany proceeds	0	0
Net cash used in financing activities - continuing operations	(83,002)	(42,775)
Net cash provided by financing activities - discontinued operations	0	0
Total cash provided by/(used in) financing activities	(83,002)	(42,775)
Effect of exchange rate on cash	0	0
Net change in cash and cash equivalents	(13,484)	(6,160)
Cash and cash equivalents at beginning of period	33,186	8,733
Less: Change in cash and cash equivalents - discontinued operations	27	(1,010)
Plus: Cash swept from discontinued operations	27	0
Cash and cash equivalents at end of period	19,702	3,583
Non-Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	(3,074)	12,692
Net cash used in operating activities - discontinued operations	0	0
Total cash provided by operating activities	(3,074)	12,692
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchase of subsidiary shares from and other decreases in noncontrolling interests	(18,023)
Purchases of property and equipment	(1,993)	(2,527)
Purchases of capitalized data and other intangible assets	(1,420)	(3,447)
Purchases of investments	(440)	(388)
Proceeds from sale of property and equipment	0
Change in restricted cash	(113)	146
Net cash used in investing activities - continuing operations	(21,989)	(6,216)
Net cash provided by investing activities - discontinued operations	0	0
Total cash used in investing activities	(21,989)	(6,216)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt		0
Repayments of long-term debt	0	0
Proceeds from issuance of shares in connection with share-based compensation	0	0
Minimum tax withholdings related to net share settlements	0	0
Excess tax benefit related to stock options	0	0
Intercompany Payments	0	(3,656)
Intercompany proceeds	22,083	0
Net cash used in financing activities - continuing operations	22,083	(3,656)
Net cash provided by financing activities - discontinued operations	0	0
Total cash provided by/(used in) financing activities	22,083	(3,656)
Effect of exchange rate on cash	137	67
Net change in cash and cash equivalents	(2,843)	2,887
Cash and cash equivalents at beginning of period	37,645	34,342
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	34,802	37,229
Consolidation, Eliminations [Member]
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net cash (used in)/provided by operating activities - continuing operations	0	0
Net cash 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 subsidiary shares from and other decreases in noncontrolling interests	0
Purchases of property and equipment	0	0
Purchases of capitalized data and other intangible assets	0	0
Purchases of investments	0	0
Proceeds from sale of property and equipment	0
Change in restricted cash	0	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
Repayments of long-term debt	0	0
Proceeds from issuance of shares in connection with share-based compensation	0	0
Minimum tax withholdings related to net share settlements	0	0
Excess tax benefit related to stock options	0	0
Intercompany Payments	99,880	46,566
Intercompany proceeds	(99,880)	(46,566)
Net cash 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
Effect of exchange rate on cash	0	0
Net change in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	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