Borrowings - Summary of Outstanding Debt (Details) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($)
Debt Instrument [Line Items]
Total Outstanding Debt	$ 4,657,585
Debt Instrument, Interest Rate, Effective Percentage	3.40%
Fixed Rate Property Mortgages [Member]
Debt Instrument [Line Items]
Contract Maturity	Sep. 01, 2048
Unsecured Debt [Member]
Debt Instrument [Line Items]
Total Outstanding Debt	$ 4,291,332
Debt Instrument, Interest Rate, Effective Percentage	3.30%
Unsecured Debt [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 3,922,000
Debt Instrument, Interest Rate, Effective Percentage	3.60%
Contract Maturity	Jan. 27, 2027
Unsecured Debt [Member] \| Commercial Paper Notes [Member] \| Variable Rate Commercial Paper Program [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 385,000
Debt Instrument, Interest Rate, Effective Percentage	0.20%
Contract Maturity	Apr. 06, 2021
Unsecured Debt [Member] \| $1 billion unsecured revolving credit facility [Member] \| Fair Market Value Adjustment and Debt Issuance Cost [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ (15,668)
Secured Debt [Member]
Debt Instrument [Line Items]
Total Outstanding Debt	366,253
Debt issuance costs	$ (3,303)
Debt Instrument, Interest Rate, Effective Percentage	4.40%
Secured Debt [Member] \| Fixed Rate Property Mortgages [Member]
Debt Instrument [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 369,556
Secured Debt [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 369,600
Debt Instrument, Interest Rate, Effective Percentage	4.40%
Contract Maturity	Dec. 31, 2048

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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Amount of investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

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