Investments TV Food Network (Details) - Television Food Network, G.P. - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Schedule of Equity Method Investments [Line Items]
Revenues, net	$ 308,758	$ 298,275	$ 606,114	$ 575,451
Operating income	197,474	188,381	390,156	370,377
Net income	$ 164,878	$ 157,213	$ 324,339	$ 305,530