Debt - Deferred Financing Costs, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Financing costs	$ 25,315		$ 25,315		$ 25,315
Less: accumulated amortization	(12,067)		(12,067)		(10,027)
Total deferred financing costs, net	13,248		13,248		15,288
Amortization of deferred financing costs	1,000	$ 1,000	2,000	$ 2,000
Unsecured term loan facility | Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Net deferred financing costs	$ 5,200		$ 5,200		$ 6,300