Leases - Narrative (Details) $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($) renewal lease	Mar. 31, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Rental income	$ 83.9	$ 76.8
Number of ground leases classified as operating \| lease	4
Number of ground leases classified as financing \| lease	2
Options to renew \| renewal	0
Weighted average remaining lease term	74 years 2 months 12 days
Operating lease costs	$ 0.9	0.9
Cash paid for operating lease liabilities	$ 0.4	$ 0.4
Chicago Illinois Office
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term	4 years

Finance Leases, Number of Ground Leases

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- Definition

Lessee, Operating Lease, Option To Renew

+ References

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- Definition

Operating Leases, Number Of Ground Leases

+ References

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- Definition

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

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

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- Definition

Amount of operating lease income from lease payments and variable lease payments paid and payable to lessor. Includes, but is not limited to, variable lease payments not included in measurement of lease receivable.

+ References

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- Definition

Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

+ References

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- Definition

Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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