Noncontrolling Interest - Common Shares and Units Activity (Details) - shares	6 Months Ended
Jun. 30, 2020
Equity Commonwealth
Increase (Decrease) in Stockholders' Equity
Ownership percentage by noncontrolling owners	0.20%
Common Shares
Increase (Decrease) in Stockholders' Equity
Balance as of beginning of period (in shares)	121,924,199
Repurchase of shares (in shares)	(894,466)
OP Unit Redemption (in shares)	0
Share-based compensation grants and vesting, net of forfeitures (in shares)	491,891
Balance as of end of period (in shares)	121,521,624
OP Units and LTIP Units \| Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity
Balance as of beginning of period (in shares)	48,660
Repurchase of shares (in shares)	0
OP Unit Redemption (in shares)	(1,000)
Share-based compensation grants and vesting, net of forfeitures (in shares)	195,856
Balance as of end of period (in shares)	243,516
Common Stock, OP Units, and LTIP Units
Increase (Decrease) in Stockholders' Equity
Balance as of beginning of period (in shares)	121,972,859
Repurchase of shares (in shares)	(894,466)
OP Unit Redemption (in shares)	(1,000)
Share-based compensation grants and vesting, net of forfeitures (in shares)	687,747
Balance as of end of period (in shares)	121,765,140

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

No definition available.

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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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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 stock bought back by the entity at the exercise price or redemption price.

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

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