Borrowings - Additional Information (Details)	6 Months Ended
Jun. 30, 2019 USD ($) Loan
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	3.80%
Commercial Paper Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Payment Terms	397
Debt Instrument, Face Amount	$ 367,000,000.0
US Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 150,000,000.0
Debt Instrument Maturity Period	2020
Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	3.70%
Number of Term Loans \| Loan	3
Unsecured Debt [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Nov. 26, 2025
Debt Instrument, Face Amount	$ 2,942,000,000
Debt Instrument, Interest Rate, Effective Percentage	4.00%
Unsecured Debt [Member] \| years to maturity [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Term	6 years 4 months 24 days
Unsecured Debt [Member] \| $1 billion unsecured revolving credit facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 1,000,000,000.0
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,500,000,000
Debt Instrument, Maturity Date	May 31, 2023
Line of Credit Facility, Amount Outstanding	$ 0
Letters of Credit Outstanding, Amount	2,500,000
Unsecured Debt [Member] \| Public Income Notes [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	2,700,000,000
Unsecured Debt [Member] \| Private Placement [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	242,000,000.0
Unsecured Debt [Member] \| Private Placement [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 242,000,000.0
Unsecured Debt [Member] \| 3.95% Notes due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Payment Terms	Interest on the 2029 Notes is payable on March 15 and September 15 of each year, beginning on September 15, 2019.
Debt Instrument, Face Amount	$ 300,000,000.0
Debt Instrument, Term	10 years
Debt Instrument, Interest Rate, Stated Percentage	3.95%
Debt Instrument, Redemption Price, Percentage	99.72%
Debt Issuance Costs, Gross	$ 2,800,000
Proceeds from Debt, Net of Issuance Costs	297,200,000
Settlement of Forward Swaps	$ 300,000,000.0
Debt Instrument, Interest Rate, Effective Percentage	4.24%
Unsecured Debt [Member] \| KeyBank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 150,000,000.0
Number of Term Loans \| Loan	1
Debt Instrument Maturity Period	2021
Unsecured Debt [Member] \| US Bank Term Loan [Member]
Debt Instrument [Line Items]
Number of Term Loans \| Loan	1
Unsecured Debt [Member] \| Wells Fargo Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 300,000,000.0
Debt Instrument, Interest Rate, Stated Percentage	2.32%
Number of Term Loans \| Loan	1
Unsecured Debt [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Mar. 01, 2022
Debt Instrument, Face Amount	$ 300,000,000
Debt Instrument, Interest Rate, Effective Percentage	2.30%
Unsecured Debt [Member] \| Wells Fargo Term Loan One [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity Period	2022
Unsecured Debt [Member] \| Wells Fargo Term Loan 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument Maturity Period	2020-01
Unsecured Debt [Member] \| Wells Fargo Term Loan 2019 [Member]
Debt Instrument [Line Items]
Repayments of Unsecured Debt	$ 300,000,000.0
Secured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	4.50%
Secured Debt [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	May 17, 2036
Debt Instrument, Interest Rate, Effective Percentage	4.50%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 663,764,000
Secured Debt [Member] \| Mortgage maturing in February 2049 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	4.43%
Proceeds from Loan Originations	$ 191,300,000
Minimum [Member] \| US Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Minimum [Member] \| Unsecured Debt [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Term	7 years
Minimum [Member] \| Unsecured Debt [Member] \| $1 billion unsecured revolving credit facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.75%
Minimum [Member] \| Unsecured Debt [Member] \| KeyBank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Minimum [Member] \| Unsecured Debt [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Maximum [Member] \| Commercial Paper Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 500,000,000.0
Maximum [Member] \| US Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.90%
Maximum [Member] \| Unsecured Debt [Member] \| Fixed Rate Debt Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Term	12 years
Maximum [Member] \| Unsecured Debt [Member] \| $1 billion unsecured revolving credit facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.45%
Maximum [Member] \| Unsecured Debt [Member] \| KeyBank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Maximum [Member] \| Unsecured Debt [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%

Debt instrument maturity period.

No definition available.

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- Definition

Debt instrument maturity year.

+ References

No definition available.

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- Definition

Number of term loans.

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No definition available.

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- Definition

Settlement of Forward Swaps

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No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

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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The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

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Cash inflow associated with loan origination (the process when securing a mortgage for a piece of real property) or lease origination.

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The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

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