Discontinued Operations Narrative (Details) - USD ($)			3 Months Ended
	Feb. 01, 2017	Jan. 31, 2017	Mar. 31, 2017	Mar. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Gain) Loss on Disposition of Business			$ 35,462,000	$ 0
Repayments of Long-term Debt			$ 584,245,000	$ 6,960,000
Amended Secured Credit Facility | Term B Loans
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Repayments of Long-term Debt	$ 400,000,000
Transition Services Agreement | Nielsen
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transition Services Period			6 months
Discontinued Operations, Disposed of by Sale | Gracenote Companies
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration		$ 560,000,000
Proceeds from Divestiture of Businesses		$ 581,000,000
Proceeds from Divestiture of Business, Working Capital Adjustment			$ 4,000,000
(Gain) Loss on Disposition of Business			(35,000,000)
Disposal Group, Including Discontinued Operation, Legal and Professional Fees			10,000,000
Discontinued Operation, Amounts of Material Contingent Liabilities Remaining			$ 0