Noncontrolling Interest - Common Shares and Units Activity (Details)	12 Months Ended
Dec. 31, 2023 shares
Equity Commonwealth
Increase (Decrease) in Stockholders' Equity
Noncontrolling ownership interest in the Operating Trust	0.21%
Common Shares, OP Units and LTIP Units
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)	109,708,144
Redemption and surrender of shares (in shares)	(3,152,604)
OP Unit Redemption (in shares)	0
Share-based compensation grants and vesting, net of forfeitures (in shares)	517,916
Ending balance (in shares)	107,073,456
Common Shares
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)	109,428,252
Redemption and surrender of shares (in shares)	(3,152,604)
OP Unit Redemption (in shares)	135,392
Share-based compensation grants and vesting, net of forfeitures (in shares)	436,398
Ending balance (in shares)	106,847,438
OP Units and LTIP Units \| Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)	279,892
Redemption and surrender of shares (in shares)	0
OP Unit Redemption (in shares)	(135,392)
Share-based compensation grants and vesting, net of forfeitures (in shares)	81,518
Ending balance (in shares)	226,018

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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Number of shares issued which are neither cancelled nor held in the treasury.

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- Definition

The number of shares issued during the period upon the conversion of units. An example of a convertible unit is an umbrella partnership real estate investment trust unit (UPREIT unit).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
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-Topic 210
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-Section S99
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-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 50
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- Definition

Number, after forfeiture, of shares or units issued under share-based payment arrangement. Excludes shares or units issued under employee stock ownership plan (ESOP).

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Number of shares that have been repurchased and retired during the period.

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