Investments Career Builder, Dose Media and CV Summarized Financial Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015		Dec. 28, 2014
CareerBuilder, LLC, Dose Media, LLC, and Classified Ventures, LLC
Schedule of Equity Method Investments [Line Items]
Revenues, net		$ 719,994	$ 698,041	[1]	$ 1,063,321	[2]
Operating income from continuing operations		93,619	84,199	[1]	147,165	[2]
Net income		89,249	80,280	[1]	$ 713,108	[3]
Current assets	[4]	222,563	266,390
Non-current assets	[4]	565,200	459,718
Current liabilities	[4]	205,643	190,977
Non-current liabilities	[4]	23,603	24,745
Redeemable non-controlling interest	[4]	$ 46,265	$ 24,666
Dose Media, LLC
Schedule of Equity Method Investments [Line Items]
Ownership in equity method investment, percent		25.00%

[1] (2) On November 25, 2015, the Company acquired a 25% interest in Dose Media. As results of operations from date of acquisition are not material to the Company in 2015, they are not included in the above table for 2015.

[2] (1) Revenues and operating income that relate to CV include results through October 1, 2014 and are presented exclusive of discontinued operations related to Apartments.com, which was sold by CV on April 1, 2014. See above for further information.

[3] (3) Net income that relates to CV include results through October 1, 2014. See above for further information.

[4] (1) Balance sheet information presented does not include CV, which was sold by the Company on October 1, 2014, as described above.