Business Segments Business Segments Footnotes (Details) - Discontinued Operations, Disposed of by Sale - Gracenote Companies - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	[1],[2]	Sep. 30, 2016	Sep. 30, 2017	[1],[2]	Sep. 30, 2016
Segment Reporting Information [Line Items]
Depreciation	$ 0		$ 3,946	$ 0		$ 9,894
Amortization	$ 0		$ 7,728	$ 0		$ 23,192

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

[2] (2)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.