Accumulated Other Comprehensive Income (Loss) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at December 31, 2017	$ (48,061)
Other comprehensive income before reclassifications	8,462
Amounts reclassified from AOCI	2,488
Balance at September 30, 2018	(37,111)
Pension and Other Post-Retirement Benefit Items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at December 31, 2017	(45,812)
Other comprehensive income before reclassifications	(3,827)
Amounts reclassified from AOCI	(124)
Balance at September 30, 2018	(49,763)
Cash Flow Hedging Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at December 31, 2017	(293)
Other comprehensive income before reclassifications	12,639
Amounts reclassified from AOCI	1,108
Balance at September 30, 2018	13,454
Foreign Currency Translation Adjustments (1)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at December 31, 2017	(1,956)
Other comprehensive income before reclassifications	(350)
Amounts reclassified from AOCI	1,504	[1]
Balance at September 30, 2018	(802)
CareerBuilder, LLC | Foreign Currency Translation Adjustments (1)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Amounts reclassified from AOCI	$ 2,000

[1] (1)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, as further described in Note 5.