Investments Marketable Equity Securities (Details) - USD ($) $ in Thousands		3 Months Ended
	Jan. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Aug. 04, 2014
Schedule of Equity Method Investments [Line Items]
Gain on investment transaction		$ 3,888	$ 4,950
tronc
Schedule of Equity Method Investments [Line Items]
tronc common stock retained, shares				381,354
Ownership percentage in common stock				1.50%
Proceeds from the sale of investment	$ 5,000
Gain on investment transaction			$ 5,000