Marketable Securities, Eldorado Resorts, Inc.- Fair Value to Amortized Cost Basis (Details) - Eldorado - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Schedule of Equity Method Investments [Line Items]
Net operating revenues	$ 167,451	$ 57,030
Operating income	12,084	1,552
Net income	$ (6,164)	$ (2,333)