Equity	3 Months Ended
Mar. 31, 2018
Equity [Abstract]
Equity	Equity During the three months ended March 31, 2018, COPT issued 677,000 common shares under its forward equity sale agreements for net proceeds of $20.0 million. COPT contributed the net proceeds from these issuances to COPLP in exchange for an equal number of units in COPLP. COPT’s remaining capacity under the forward equity sale agreements was 6.8 million common shares as of March 31, 2018. During the three months ended March 31, 2018, certain COPLP limited partners converted 53,817 common units in COPLP for an equal number of common shares in COPT. As of March 31, 2018, COPT had remaining capacity under its at-the-market stock offering program equal to an aggregate gross sales price of $70.0 million in common share sales. See Note 14 for disclosure of COPT common share and COPLP common unit activity pertaining to our share-based compensation plans.

Equity

3 Months Ended

Mar. 31, 2018

During the three months ended March 31, 2018, COPT issued 677,000 common shares under its forward equity sale agreements for net proceeds of $20.0 million. COPT contributed the net proceeds from these issuances to COPLP in exchange for an equal number of units in COPLP. COPT’s remaining capacity under the forward equity sale agreements was 6.8 million common shares as of March 31, 2018.

During the three months ended March 31, 2018, certain COPLP limited partners converted 53,817 common units in COPLP for an equal number of common shares in COPT.

As of March 31, 2018, COPT had remaining capacity under its at-the-market stock offering program equal to an aggregate gross sales price of $70.0 million in common share sales.

See Note 14 for disclosure of COPT common share and COPLP common unit activity pertaining to our share-based compensation plans.