Debt - Deferred Financing Costs, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Financing costs	$ 25,315		$ 25,315		$ 25,315
Less: accumulated amortization	(12,991)		(12,991)		(10,027)
Total deferred financing costs, net	12,324		12,324		15,288
Amortization related to deferred financing costs	900	$ 1,100	2,900	$ 3,100
Unsecured term loan facility | Unsecured revolving credit facility
Debt Instrument [Line Items]
Net deferred financing costs	$ 4,700		$ 4,700		$ 6,300