Summary of Significant Accounting Policies - Schedule of Material Changes Between Cash Flow Classifications due to Substantial Debt Prepayment Penalties (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt	$ 1,532	$ 1,130
Net (gain) loss on debt extinguishment	22,110	11,698
Net cash provided by operating activities	361,018	303,904
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash provided by (used for) investing activities	147,298	(72,642)
CASH FLOWS FROM FINANCING ACTIVITIES:
Commercial paper proceeds	1,107,561	1,310,188
Net cash (used for) financing activities	(514,367)	(264,127)
Cash and cash equivalents, beginning of period	50,647
Cash and cash equivalents and restricted deposits, beginning of period	100,762	219,088
Cash and cash equivalents, end of period	44,453	42,139
Cash and cash equivalents and restricted deposits, end of period	94,711	186,223
Mortgage Notes Payable, Net [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage notes payable, net: Net gain (loss) on debt extinguishment	$ (22,110)	(11,698)
Scenario, Previously Reported [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		1,637
(Increase) decrease in deposits - restricted		256
(Increase) decrease in mortgage deposits		315
Net cash provided by operating activities		293,284
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		637
(Increase) decrease in mortgage deposits		(1,030)
Net cash provided by (used for) investing activities		(73,035)
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		(2,381)
Commercial paper proceeds		1,309,681
Net cash (used for) financing activities		(255,317)
Cash and cash equivalents, beginning of period		77,207
Cash and cash equivalents, end of period		42,139
Reclassification Adjustments [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		(507)
Net (gain) loss on debt extinguishment		11,698
(Increase) decrease in deposits - restricted		(256)
(Increase) decrease in mortgage deposits		(315)
Net cash provided by operating activities		10,620
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		(637)
(Increase) decrease in mortgage deposits		1,030
Net cash provided by (used for) investing activities		393
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		2,381
Commercial paper proceeds		507
Net cash (used for) financing activities		(8,810)
(adjustments for restricted deposits, beginning of period)		141,881
(adjustments for restricted deposits, end of period)		144,084
Reclassification Adjustments [Member] | Mortgage Notes Payable, Net [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage notes payable, net: Net gain (loss) on debt extinguishment		$ (11,698)