Discontinued Operations Gracenote Companies Cash Flows (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015	Jan. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock-based compensation		$ 32,933		$ 37,189	$ 32,493
Depreciation (2)		56,314		72,409	74,289
Amortization (2)		166,679		196,663	195,230
Acquisitions, net of cash acquired		0		0	74,959
Capital expenditures		66,832		99,659	89,084
Net proceeds from the sale of business		557,793		0	0
Settlements of contingent consideration, net		0		(3,636)	1,174
Cash and cash equivalents classified as discontinued operations		0		12,751	14,824
Gracenote Companies | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock-based compensation		1,992		4,196	2,239
Depreciation (2)		0	[1],[2]	13,584	9,735
Amortization (2)		0	[1],[2]	29,999	28,826
Acquisitions, net of cash acquired	[3]	0	[2]	0	(58,996)
Capital expenditures	[3]	1,578	[2]	23,548	23,626
Net proceeds from the sale of business	[4]	557,793	[2]	0	0
Settlements of contingent consideration, net	[3]	0	[2]	(3,636)	$ 1,174
Proceeds from Divestiture of Businesses		584,000
Cash and cash equivalents classified as discontinued operations				$ 12,751		$ 17,000
Disposal Groups, Including Discontinued Operations, Selling Costs		$ 9,000

[1] No depreciation expense or amortization expense was recorded by the Company in 2017 as the Gracenote Companies’ assets were held for sale as of December 31, 2016.

[2] Results of operations for the Gracenote Companies are reflected through January 31, 2017, the date of the Gracenote Sale.

[3] Non-cash investing and financing activities of Digital and Data businesses included in the Gracenote Sale were immaterial

[4] Net proceeds from the sale of business reflects the gross proceeds from the Gracenote sale of $584 million, net of $17 million of the Gracenote Companies’ cash and cash equivalents included in the sale and $9 million of selling costs.