Real Estate Investments and Related Intangibles - Impairment of Real Estate Investments Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) restaurant	Dec. 31, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charges	$ 50,548	$ 182,819	$ 91,755
Tenant file for bankruptcy, number of restaurants | restaurant		59
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of real estate assets deemed to be impaired	161,900	$ 668,200	340,100
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value of real estate assets deemed to be impaired	$ 111,400	$ 485,400	$ 248,300