Summary of Significant Accounting Policies - Master Lease Financing Obligations (Details) - USD ($) $ in Thousands					1 Months Ended	12 Months Ended
	Nov. 01, 2018	Oct. 15, 2018	Jul. 30, 2014	Nov. 01, 2013	Sep. 30, 2014	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Capital Leased Assets [Line Items]
Remaining lease term		7 years 6 months
Proceeds from the sale of real estate assets in conjunction with acquisitions						$ 250,000	$ 82,600	$ 0
Penn Master Lease
Capital Leased Assets [Line Items]
Lease term				35 years
Discount rate				9.70%
Rent adjustment increase (decrease)	$ (11,300)		$ (6,200)		$ 19,000
Pinnacle Master Lease
Capital Leased Assets [Line Items]
Discount rate		7.30%
Remaining lease term		32 years 6 months
Proceeds from the sale of real estate assets in conjunction with acquisitions		$ 250,000
Rent adjustment increase (decrease)		$ 25,000
Effective yield		9.60%