Debt - Mortgage Notes Payable - Summary of Mortgage Notes Payable Activity (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Mortgage notes payable, net beginning balance	$ 1,941,610
Proceeds	505,375	$ 295,713
Lump sum payoffs	(127,767)	(723,021)
Scheduled principal repayments	(5,821)
Amortization of premiums/ discounts	1,791	$ 8,017
Amortization of deferred financing costs, net	(1,355)
Mortgage notes payable, net ending balance	2,313,833
Fixed Rate Debt [Member] | Secured – Conventional [Member]
Debt Instrument [Line Items]
Mortgage notes payable, net beginning balance	1,574,699
Proceeds	495,000
Lump sum payoffs	(127,767)
Scheduled principal repayments	(5,821)
Amortization of premiums/ discounts	858
Amortization of deferred financing costs, net	(1,683)
Mortgage notes payable, net ending balance	1,935,286
Floating Rate Debt [Member]
Debt Instrument [Line Items]
Mortgage notes payable, net beginning balance	366,911
Proceeds	10,375
Amortization of premiums/ discounts	933
Amortization of deferred financing costs, net	328
Mortgage notes payable, net ending balance	378,547
Floating Rate Debt [Member] | Secured – Conventional [Member]
Debt Instrument [Line Items]
Mortgage notes payable, net beginning balance	7,050
Proceeds	10,375
Amortization of deferred financing costs, net	180
Mortgage notes payable, net ending balance	17,605
Floating Rate Debt [Member] | Secured – Tax Exempt [Member]
Debt Instrument [Line Items]
Mortgage notes payable, net beginning balance	359,861
Amortization of premiums/ discounts	933
Amortization of deferred financing costs, net	148
Mortgage notes payable, net ending balance	$ 360,942