Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Rental revenue	$ 101,121	$ 101,347	$ 201,955	$ 201,962
Tenant recoveries and other real estate operations revenue	28,041	26,950	55,485	53,102
Construction contract and other service revenues	17,581	23,138	44,779	36,172
Total revenues	146,743	151,435	302,219	291,236
Expenses
Property operating expenses	49,446	48,628	100,397	97,147
Depreciation and amortization associated with real estate operations	33,190	32,793	66,702	65,852
Construction contract and other service expenses	16,941	22,315	43,157	34,801
Impairment losses	0	1,625	0	1,625
General, administrative and leasing expenses	7,628	7,859	14,920	16,470
Business development expenses and land carry costs	1,234	1,597	2,848	3,290
Total operating expenses	108,439	114,817	228,024	219,185
Operating income	38,304	36,618	74,195	72,051
Interest expense	(18,945)	(19,163)	(37,729)	(38,157)
Interest and other income	1,439	1,583	2,798	3,309
Loss on early extinguishment of debt	0	(513)	0	(513)
Income before equity in income of unconsolidated entities and income taxes	20,798	18,525	39,264	36,690
Equity in income of unconsolidated entities	373	370	746	747
Income tax expense	(63)	(48)	(118)	(88)
Income before gain on sales of real estate	21,108	18,847	39,892	37,349
Gain on sales of real estate	(23)	12	(27)	4,250
Net income	21,085	18,859	39,865	41,599
Net income attributable to noncontrolling interests:
Common units in COPLP	(608)	(261)	(1,152)	(883)
Preferred units in COPLP	(165)	(165)	(330)	(330)
Other consolidated entities	(878)	(907)	(1,799)	(1,841)
Net income attributable to COPT	19,434	17,526	36,584	38,545
'Preferred share/unit dividends/distributions	0	(3,039)	0	(6,219)
Issuance costs associated with redeemed preferred shares/units	0	(6,847)	0	(6,847)
Net income attributable to COPT common shareholders	$ 19,434	$ 7,640	$ 36,584	$ 25,479
Earnings per common share:
Net income attributable to COPT common shareholders - basic (in dollars per share/unit)	$ 0.19	$ 0.08	$ 0.36	$ 0.26
Net income attributable to COPT common shareholders - diluted (in dollars per share/unit)	0.19	0.08	0.36	0.26
Dividends declared per common share/unit (in dollars per share)	$ 0.2750	$ 0.275	$ 0.55	$ 0.55
Corporate Office Properties, L.P.
Revenues
Rental revenue	$ 101,121	$ 101,347	$ 201,955	$ 201,962
Tenant recoveries and other real estate operations revenue	28,041	26,950	55,485	53,102
Construction contract and other service revenues	17,581	23,138	44,779	36,172
Total revenues	146,743	151,435	302,219	291,236
Expenses
Property operating expenses	49,446	48,628	100,397	97,147
Depreciation and amortization associated with real estate operations	33,190	32,793	66,702	65,852
Construction contract and other service expenses	16,941	22,315	43,157	34,801
Impairment losses	0	1,625	0	1,625
General, administrative and leasing expenses	7,628	7,859	14,920	16,470
Business development expenses and land carry costs	1,234	1,597	2,848	3,290
Total operating expenses	108,439	114,817	228,024	219,185
Operating income	38,304	36,618	74,195	72,051
Interest expense	(18,945)	(19,163)	(37,729)	(38,157)
Interest and other income	1,439	1,583	2,798	3,309
Loss on early extinguishment of debt	0	(513)	0	(513)
Income before equity in income of unconsolidated entities and income taxes	20,798	18,525	39,264	36,690
Equity in income of unconsolidated entities	373	370	746	747
Income tax expense	(63)	(48)	(118)	(88)
Income before gain on sales of real estate	21,108	18,847	39,892	37,349
Gain on sales of real estate	(23)	12	(27)	4,250
Net income	21,085	18,859	39,865	41,599
Net income attributable to noncontrolling interests:
Net income attributable to noncontrolling interests in consolidated entities	(878)	(907)	(1,799)	(1,841)
Net income attributable to COPT	20,207	17,952	38,066	39,758
'Preferred share/unit dividends/distributions	(165)	(3,204)	(330)	(6,549)
Issuance costs associated with redeemed preferred shares/units	0	(6,847)	0	(6,847)
Net income attributable to COPT common shareholders	$ 20,042	$ 7,901	$ 37,736	$ 26,362
Earnings per common share:
Net income attributable to COPT common shareholders - basic (in dollars per share/unit)	$ 0.19	$ 0.08	$ 0.36	$ 0.26
Net income attributable to COPT common shareholders - diluted (in dollars per share/unit)	0.19	0.08	0.36	0.26
Dividends declared per common share/unit (in dollars per share)	$ 0.275	$ 0.275	$ 0.55	$ 0.55