Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, balance at beginning of the period		$ (48,061)
Cumulative effect of a change in accounting principle		0	$ 164
Accumulated other comprehensive (loss) income, balance at the end of the period		(104,967)	(48,061)
Cumulative translation adjustments		(42,575)	33,721	$ (10,766)
Pension and other Post-Retirement Benefit Items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, balance at beginning of the period		(45,812)	(64,883)
Other comprehensive income (loss) before reclassifications		(48,752)	19,231
Amounts reclassified from AOCI		(165)	(160)
Cumulative effect of a change in accounting principle	[1]	(13,509)
Accumulated other comprehensive (loss) income, balance at the end of the period		(108,238)	(45,812)	(64,883)
Marketable Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, balance at beginning of the period		0	3,075
Other comprehensive income (loss) before reclassifications		0	(95)
Amounts reclassified from AOCI		0	(2,980)
Cumulative effect of a change in accounting principle	[1]	0
Accumulated other comprehensive (loss) income, balance at the end of the period		0	0	3,075
Cash Flow Hedging Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, balance at beginning of the period		(293)	0
Other comprehensive income (loss) before reclassifications		4,397	(3,591)
Amounts reclassified from AOCI		1,074	3,298
Cumulative effect of a change in accounting principle	[1]	(614)
Accumulated other comprehensive (loss) income, balance at the end of the period		4,564	(293)	0
Foreign Currency Translation Adjustments (1)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, balance at beginning of the period		(1,956)	(19,974)
Other comprehensive income (loss) before reclassifications		(633)	5,253
Amounts reclassified from AOCI	[2]	1,504	12,765
Cumulative effect of a change in accounting principle	[1]	(208)
Accumulated other comprehensive (loss) income, balance at the end of the period		(1,293)	(1,956)	(19,974)
Foreign Currency Translation Adjustments (1) | CareerBuilder, LLC
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative translation adjustments		2,000	4,000
Foreign Currency Translation Adjustments (1) | Gracenote Companies
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative translation adjustments			9,000
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive (loss) income, balance at beginning of the period		(48,061)	(81,782)
Other comprehensive income (loss) before reclassifications		(44,988)	20,798
Amounts reclassified from AOCI		2,413	12,923
Cumulative effect of a change in accounting principle	[1]	(14,331)
Accumulated other comprehensive (loss) income, balance at the end of the period		(104,967)	(48,061)	(81,782)
Cumulative translation adjustments		$ (42,575)	$ 33,721	$ (10,766)

[1] (2)See Note 1 for additional information on the adoption of ASU 2018-02.

[2] (1)In 2017, amounts reclassified from AOCI included $9 million of cumulative translation adjustments as a result of the Gracenote Sale, which are included in income (loss) from discontinued operations, net of taxes, and $4 million of cumulative translation adjustments as a result of the CareerBuilder impairment, which are included in write-downs of investments, in the Company’s Consolidated Statements of Operations. In 2018, amounts reclassified from AOCI included $2 million of cumulative translation adjustments as a result of the Company’s sale of its remaining ownership interest in CareerBuilder. See Note 6 for the discussion of the Company’s equity-method investments.