Summary of Significant Accounting Policies - Schedule of Material Changes Between Cash Flow Classifications due to Substantial Debt Prepayment Penalties (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt	$ 21,360	$ 2,018
Net (gain) loss on debt extinguishment	22,110	12,258
Net cash provided by operating activities	1,044,191	970,136
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash provided by (used for) investing activities	(268,820)	(515,775)
CASH FLOWS FROM FINANCING ACTIVITIES:
Commercial paper proceeds	9,624,610	3,891,596
Net cash (used for) financing activities	(787,383)	(579,273)
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	32,995	46,565
Cash and cash equivalents and restricted deposits, end of period	88,750	94,176
Scenario, Previously Reported [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		4,939
(Increase) decrease in deposits - restricted		788
(Increase) decrease in mortgage deposits		1,447
Net cash provided by operating activities		963,034
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		39,519
(Increase) decrease in mortgage deposits		(4,541)
Net cash provided by (used for) investing activities		(480,797)
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		57,057
Commercial paper proceeds		3,888,675
Net cash (used for) financing activities		(512,879)
Cash and cash equivalents, beginning of period		77,207
Cash and cash equivalents, end of period		46,565
Reclassification Adjustments [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Amortization of discounts and premiums on debt		(2,921)
Net (gain) loss on debt extinguishment		12,258
(Increase) decrease in deposits - restricted		(788)
(Increase) decrease in mortgage deposits		(1,447)
Net cash provided by operating activities		7,102
CASH FLOWS FROM INVESTING ACTIVITIES:
(Increase) decrease in deposits on real estate acquisitions and investments, net		(39,519)
(Increase) decrease in mortgage deposits		4,541
Net cash provided by (used for) investing activities		(34,978)
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage deposits		(57,057)
Commercial paper proceeds		2,921
Net cash (used for) financing activities		(66,394)
(adjustments for restricted deposits, beginning of period)		141,881
(adjustments for restricted deposits, end of period)		47,611
Mortgage Notes Payable, Net [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage notes payable, net: Net gain (loss) on debt extinguishment	$ (22,110)	(12,258)
Mortgage Notes Payable, Net [Member] \| Reclassification Adjustments [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Mortgage notes payable, net: Net gain (loss) on debt extinguishment		$ (12,258)

Adjustments for restricted deposits.

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