Columbia Property Trust (CXP) 10-K 13 Feb 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
Entity Information
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-36113
Entity Registrant Name	COLUMBIA PROPERTY TRUST, INC.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	20-0068852
Entity Address, Address Line One	315 Park Avenue South
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10010
City Area Code	212
Local Phone Number	687-0800
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CXP
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Public Float			$ 1,744,911,617
Entity Common Stock, Shares Outstanding		115,232,240
Entity Central Index Key	0001252849
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Documents Incorporated by Reference	Registrant incorporates by reference portions of the Columbia Property Trust, Inc. Definitive Proxy Statement for the 2020 Annual Meeting of Stockholders (Items 10, 11, 12, 13, and 14 of Part III) to be filed prior to April 29, 2020.
Columbia Property Trust Operating Partnership, L.P.
Entity Information
Entity File Number	333-175623
Entity Registrant Name	COLUMBIA PROPERTY TRUST OPERATING PARTNERSHIP, L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-0068907
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Entity Emerging Growth Company	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Real Estate Assets, at Cost:
Land	$ 870,352	$ 817,975
Buildings and improvements, less accumulated depreciation of $281,248 and $403,355, as of December 31, 2019 and 2018, respectively	1,719,207	1,910,041
Intangible lease assets, less accumulated amortization of $58,659 and $84,881, as of December 31, 2019 and 2018, respectively	61,025	98,540
Construction in progress	53,621	33,800
Real estate assets held for sale, less accumulated depreciation and amortization of $22,464 as of December 31, 2019	214,956	0
Total real estate assets	2,919,161	2,860,356
Operating lease assets	29,470
Investments in unconsolidated joint ventures	1,054,460	1,071,353
Cash and cash equivalents	12,303	17,118
Tenant receivables, net of allowance for doubtful accounts of $4 as of December 31, 2018	2,464	3,258
Straight-line rent receivable	77,330	87,159
Prepaid Expense and Other Assets	21,484	23,218
Intangible lease origination costs, less accumulated amortization of $33,731 and $65,348, as of December 31, 2019 and 2018, respectively	27,971	34,092
Deferred lease costs, less accumulated amortization of $14,272 and $19,342, as of December 31, 2019 and 2018, respectively	76,385	77,439
Other assets held for sale, less accumulated amortization of $3,971 as of December 31, 2019	23,917	0
Total assets	4,244,945	4,173,993
Liabilities:
Line of credit and notes payable, net of deferred financing costs of $2,084 and $2,692, as of December 31, 2019 and 2018, respectively	781,916	629,308
Bonds payable, net of discount of $1,124 and $1,304 and deferred financing costs of $3,552 and $4,158, as of December 31, 2019 and 2018, respectively	695,324	694,538
Operating lease liabilities	2,186
Accounts payable, accrued expenses, and accrued capital expenditures	70,845	49,117
Dividends payable	24,209	23,340
Deferred income	16,955	15,593
Intangible lease liabilities, less accumulated amortization of $15,127 and $21,766, as of December 31, 2019 and 2018, respectively	21,839	21,081
Liabilities held for sale	3,054	0
Total liabilities	1,616,328	1,432,977
Commitments and Contingencies (Note 7)	0	0
Equity:
Common stock, $0.01 par value, 225,000,000 shares authorized, 115,280,597 and 116,698,033 shares issued and outstanding as of December 31, 2019 and 2018, respectively	1,153	1,167
Additional paid-in capital	4,392,322	4,421,587
Cumulative distributions in excess of earnings	(1,769,234)	(1,684,082)
Accumulated other comprehensive income (loss)	(1,101)	2,344
Total stockholders' equity attributable to Columbia Property Trust	2,623,140	2,741,016
Noncontrolling interest in consolidated joint venture	5,477	0
Total equity	2,628,617	2,741,016
Partners' Capital:
Total liabilities and equity	4,244,945	4,173,993
Columbia Property Trust Operating Partnership, L.P.
Real Estate Assets, at Cost:
Land	843,546	775,656
Buildings and improvements, less accumulated depreciation of $281,248 and $403,355, as of December 31, 2019 and 2018, respectively	1,668,358	1,720,271
Intangible lease assets, less accumulated amortization of $58,659 and $84,881, as of December 31, 2019 and 2018, respectively	61,025	98,540
Construction in progress	51,240	32,526
Real estate assets held for sale, less accumulated depreciation and amortization of $22,464 as of December 31, 2019	69,274	0
Total real estate assets	2,693,443	2,626,993
Operating lease assets	27,843
Investments in unconsolidated joint ventures	1,054,460	1,071,353
Cash and cash equivalents	9,522	10,931
Tenant receivables, net of allowance for doubtful accounts of $4 as of December 31, 2018	2,039	2,956
Straight-line rent receivable	70,985	71,675
Prepaid Expense and Other Assets	21,044	21,680
Intangible lease origination costs, less accumulated amortization of $33,731 and $65,348, as of December 31, 2019 and 2018, respectively	27,971	34,092
Deferred lease costs, less accumulated amortization of $14,272 and $19,342, as of December 31, 2019 and 2018, respectively	73,699	65,484
Other assets held for sale, less accumulated amortization of $3,971 as of December 31, 2019	5,573	0
Total assets	3,986,579	3,905,164
Liabilities:
Line of credit and notes payable, net of deferred financing costs of $2,084 and $2,692, as of December 31, 2019 and 2018, respectively	781,916	629,308
Bonds payable, net of discount of $1,124 and $1,304 and deferred financing costs of $3,552 and $4,158, as of December 31, 2019 and 2018, respectively	695,324	694,538
Accounts payable, accrued expenses, and accrued capital expenditures	68,535	36,133
Due to affiliates	140,444	141,145
Deferred income	16,299	13,245
Intangible lease liabilities, less accumulated amortization of $15,127 and $21,766, as of December 31, 2019 and 2018, respectively	21,839	21,081
Liabilities held for sale	1,809	0
Total liabilities	1,726,166	1,535,450
Commitments and Contingencies (Note 7)	0	0
Partners' Capital:
Partners' Capital	2,254,936	2,369,714
Noncontrolling interest in consolidated joint venture	5,477	0
Total capital	2,260,413	2,369,714
Total liabilities and equity	$ 3,986,579	$ 3,905,164

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Building and improvements, accumulated depreciation	$ 281,248	$ 403,355
Intangible lease assets, accumulated amortization	58,659	84,881
Depreciation and amortization	80,543
Allowance for doubtful accounts		4
Intangible lease origination costs, accumulated amortization	33,731	65,348
Accumulated amortization for deferred lease cost	16,732	27,735
Held for sale accumulated amortization	10,222
Deferred financing costs	2,084	2,692
Bonds payable, discount	1,124	1,304
Intangible lease liabilities, accumulated amortization	$ 15,127	$ 21,766
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	225,000,000	225,000,000
Common stock, shares issued	115,280,597	116,698,033
Common stock, shares outstanding	115,280,597	116,698,033
Term Loans
Deferred financing costs	$ 2,084	$ 2,692
Unsecured Debt
Deferred financing costs	3,552	4,158
Columbia Property Trust Operating Partnership, L.P.
Building and improvements, accumulated depreciation	252,034	324,426
Intangible lease assets, accumulated amortization	58,658	84,881
Depreciation and amortization	22,464
Allowance for doubtful accounts		4
Intangible lease origination costs, accumulated amortization	33,731	65,348
Accumulated amortization for deferred lease cost	14,272	19,342
Held for sale accumulated amortization	3,971
Bonds payable, discount	1,124	1,304
Intangible lease liabilities, accumulated amortization	15,127	21,766
Columbia Property Trust Operating Partnership, L.P. | Term Loans
Deferred financing costs	2,084	2,692
Columbia Property Trust Operating Partnership, L.P. | Unsecured Debt
Deferred financing costs	$ 3,552	$ 4,158

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Operating Lease, Lease Income	$ 276,149	$ 283,252	$ 280,570
Total revenue	288,837	297,943	289,000
Expenses:
Depreciation	78,292	81,795	80,394
Amortization	27,908	32,554	32,403
Impairment loss on real estate assets	43,941	30,812	0
General and administrative expense - corporate	32,779	32,979	34,966
General and administrative – joint venture	3,567	3,108	1,454
Pre-acquisition costs (Note 16)	6,398	0	0
Costs and expenses	286,789	270,915	240,029
Other Income (Expense):
Interest expense	(43,170)	(56,499)	(60,516)
Gain (loss) on extinguishment of debt	0	23,340	(325)
Interest and other income	173	6,894	9,529
Gain on sale of unconsolidated joint venture interests	0	762	0
Income tax benefit (expense)	(21)	(37)	213
Income from unconsolidated joint ventures	8,004	8,003	2,651
Gains on sales of real estate assets	42,030	0	175,518
Nonoperating income (expense)	7,016	(17,537)	127,070
Net income	9,064	9,491	176,041
Less: net loss attributable to non-controlling interest in consolidated joint venture	133	0	0
Net income attributable to common stockholders	$ 9,197	$ 9,491	$ 176,041
Per-Share Information – Basic:
Net income attributable to common stockholders (in dollars per share)	$ 0.08	$ 0.08	$ 1.45
Weighted-average common shares outstanding – basic (in shares)	116,261	117,888	120,795
Per-Share Information – Diluted:
Net income attributable to common stockholders (in dollars per share)	$ 0.08	$ 0.08	$ 1.45
Weighted-average common shares – diluted (in shares)	116,458	118,311	121,159
Hotel income/operating costs
Revenues:
Revenue	$ 0	$ 0	$ 1,339
Expenses:
Cost of goods and services sold	0	0	2,089
Asset and property management fee income/expenses
Revenues:
Revenue	7,544	7,384	3,782
Expenses:
Cost of goods and services sold	629	854	918
Other property income
Revenues:
Revenue	5,144	7,307	3,309
Property operating costs
Expenses:
Cost of goods and services sold	93,275	88,813	87,805
Columbia Property Trust Operating Partnership, L.P.
Revenues:
Operating Lease, Lease Income	248,838	254,988	252,149
Total revenue	248,937	256,311	251,540
Expenses:
Depreciation	67,773	71,934	72,010
Amortization	26,663	31,451	31,035
Impairment loss on real estate assets	43,941	30,812	0
General and administrative expense - corporate	7,927	9,469	9,232
General and administrative – joint venture	43	0	0
Pre-acquisition costs (Note 16)	4,160	0	0
Costs and expenses	236,664	225,048	193,973
Other Income (Expense):
Interest expense	(49,470)	(66,046)	(73,877)
Gain (loss) on extinguishment of debt	0	23,340	(325)
Interest and other income	64	6,894	6,784
Gain on sale of unconsolidated joint venture interests	0	762	0
Income tax benefit (expense)	0	0	(3)
Income from unconsolidated joint ventures	8,004	8,003	2,651
Gains on sales of real estate assets	42,030	0	170,733
Nonoperating income (expense)	628	(27,047)	105,963
Net income	12,901	4,216	163,530
Less: net loss attributable to non-controlling interest in consolidated joint venture	133	0	0
Net income attributable to common stockholders	13,034	4,216	163,530
Columbia Property Trust Operating Partnership, L.P. | Asset and property management fee income/expenses
Expenses:
Cost of goods and services sold	3,952	3,856	3,977
Columbia Property Trust Operating Partnership, L.P. | Other property income
Revenues:
Revenue	99	1,323	(609)
Columbia Property Trust Operating Partnership, L.P. | Property operating costs
Expenses:
Cost of goods and services sold	$ 82,205	$ 77,526	$ 77,719

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net income	$ 9,064	$ 9,491	$ 176,041
Net income	9,197	9,491	176,041
Market value adjustment to interest rate swaps	(3,445)	1,441	1,786
Comprehensive income	5,619	10,932	177,827
Less: net loss attributable to non-controlling interest in consolidated joint venture	133	0	0
Comprehensive income attributable to common stockholders	5,752	10,932	177,827
Columbia Property Trust Operating Partnership, L.P.
Net income	12,901	4,216	163,530
Net income	13,034	4,216	163,530
Market value adjustment to interest rate swaps	(3,445)	1,441	1,786
Comprehensive income	9,456	5,657	165,316
Less: net loss attributable to non-controlling interest in consolidated joint venture	133	0	0
Comprehensive income attributable to common stockholders	$ 9,589	$ 5,657	$ 165,316

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Cumulative Distributions in Excess of Earnings	Accumulated Other Comprehensive Income (Loss)	Total	Noncontrolling Interests
Balance, shares at beginning of period at Dec. 31, 2016		122,184,000
Balance, value at beginning of period at Dec. 31, 2016	$ 2,502,768	$ 1,221	$ 4,538,912	$ (2,036,482)	$ (883)	$ 2,502,768
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchases of common stock, shares		(2,682,000)
Repurchases of common stock	(57,628)	$ (26)	(57,602)			(57,628)
Common stock issued to employees and directors, and amortized (net of income tax witholdings), shares		287,000
Common stock issued to employees and directors, and amortized (net of income tax witholdings)	5,764	$ 3	5,761			5,764
Distributions to common stockholders	(96,795)			(96,795)		(96,795)
Net income	176,041			176,041		176,041
Market value adjustment to interest rate swaps	1,786				1,786	1,786
Balance, shares at end of period at Dec. 31, 2017		119,789,000
Balance, value at end of period at Dec. 31, 2017	2,531,936	$ 1,198	4,487,071	(1,957,236)	903	2,531,936
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchases of common stock, shares		(3,240,000)
Repurchases of common stock	(70,520)	$ (32)	(70,488)			(70,520)
Common stock issued to employees and directors, and amortized (net of income tax witholdings), shares		149,000
Common stock issued to employees and directors, and amortized (net of income tax witholdings)	5,005	$ 1	5,004			5,005
Distributions to common stockholders	(94,435)			(94,435)		(94,435)
Net income	9,491			9,491		9,491
Market value adjustment to interest rate swaps	$ 1,441				1,441	1,441
Balance, shares at end of period at Dec. 31, 2018	116,698,033	116,698,000
Balance, value at end of period at Dec. 31, 2018	$ 2,741,016	$ 1,167	4,421,587	(1,684,082)	2,344	2,741,016	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchases of common stock, shares		(1,616,000)
Repurchases of common stock	(33,516)	$ (16)	(33,500)			(33,516)
Common stock issued to employees and directors, and amortized (net of income tax witholdings), shares		198,000
Common stock issued to employees and directors, and amortized (net of income tax witholdings)	4,237	$ 2	4,235			4,237
Distributions to common stockholders	(94,349)			(94,349)		(94,349)
Contributions from noncontrolling interest in consolidated joint venture	5,610						5,610
Net income	9,064			9,197		9,197	(133)
Market value adjustment to interest rate swaps	$ (3,445)				(3,445)	(3,445)
Balance, shares at end of period at Dec. 31, 2019	115,280,597	115,280,000
Balance, value at end of period at Dec. 31, 2019	$ 2,628,617	$ 1,153	$ 4,392,322	$ (1,769,234)	$ (1,101)	$ 2,623,140	$ 5,477

Consolidated Statements of Eq_2

Consolidated Statements of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Common Stock
Distributions to common stockholders (in dollars per share)	$ 0.81	$ 0.80	$ 0.80

Consolidated Statements of Capi

Consolidated Statements of Capital - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income	$ 9,064	$ 9,491	$ 176,041
Market value adjustment to interest rate swaps	(3,445)	1,441	1,786
Columbia Property Trust Operating Partnership, L.P.
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	2,369,714	1,996,020	1,768,862
Cumulative-effect adjustment for the adoption of ASU				$ 357,755
Contributions	17,663	177,833	296,083
Distributions	(136,420)	(167,551)	(234,241)
Net income	12,901	4,216	163,530
Market value adjustment to interest rate swaps	(3,445)	1,441	1,786
Ending balance	2,260,413	2,369,714	1,996,020
Columbia Property Trust, Inc.
Increase (Decrease) in Partners' Capital [Roll Forward]
Contributions	12,053
Columbia Property Trust, Inc. | Columbia Property Trust Operating Partnership, L.P.
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	2,369,714	1,996,020	1,768,862
Cumulative-effect adjustment for the adoption of ASU				$ 357,755
Contributions		177,833	296,083
Distributions	(136,420)	(167,551)	(234,241)
Net income	13,034	4,216	163,530
Market value adjustment to interest rate swaps	(3,445)	1,441	1,786
Ending balance	2,254,936	2,369,714	1,996,020
Noncontrolling Interests | Columbia Property Trust Operating Partnership, L.P.
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	0	0	0
Contributions	5,610
Net income	(133)
Ending balance	$ 5,477	$ 0	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Flows From Operating Activities:
Net income	$ 9,064	$ 9,491	$ 176,041
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Straight-line rental income	(13,230)	(25,952)	(32,737)
Noncash operating lease expense	720	0	0
Depreciation	78,292	81,795	80,394
Amortization	23,546	29,401	31,907
Impairment loss on real estate assets	43,941	30,812	0
Noncash interest expense	2,562	3,103	3,009
(Gain) loss on extinguishment of debt	0	(23,340)	325
Gains on sales of real estate assets	(42,030)	0	(175,518)
Income from unconsolidated joint ventures	(8,004)	(8,003)	(2,651)
Distributions of earnings from unconsolidated joint ventures	27,977	28,802	3,681
Gain on sale of unconsolidated joint venture interest	0	(762)	0
Stock-based compensation expense	6,622	6,966	7,580
Changes in Assets and Liabilities, Net of Acquisitions and Dispositions:
Decrease (increase) in tenant receivables, net	697	(2,947)	4,222
Decrease (increase) in prepaid expenses and other assets	(1,539)	7,871	(1,754)
Decrease (increase) in accounts payable and accrued expenses	5,560	(36,724)	(28,133)
Increase (decrease) in deferred income	3,265	(2,888)	(4,442)
Net cash provided by operating activities	137,443	97,625	61,924
Cash Flows From Investing Activities:
Net proceeds from the sale of real estate	375,004	284,608	737,631
Net proceeds from the sale of investments in unconsolidated joint ventures	0	235,083	0
Real estate acquisitions and prepaid transaction costs	(453,128)	(23,034)	(604,769)
Capital improvements and development costs	(66,994)	(71,033)	(86,805)
Deferred lease costs paid	(22,307)	(24,816)	(26,722)
Investments in unconsolidated joint ventures	(17,134)	(38,763)	(369,043)
Distributions in excess of earnings from unconsolidated joint ventures	14,250	13,685	1,985
Net cash provided by (used in) investing activities	(170,309)	375,730	(347,723)
Cash Flows From Financing Activities:
Financing costs paid	(162)	(5,078)	(1,269)
Proceeds from lines of credit and notes payable	802,000	579,000	783,000
Repayments of lines of credit and notes payable	(650,000)	(872,175)	(533,427)
Distributions paid to stockholders	(93,480)	(95,056)	(109,561)
Redemptions of common stock	(35,917)	(72,495)	(59,462)
Contribution from noncontrolling interest in consolidated joint venture	5,610	0	0
Net cash provided by (used in) financing activities	28,051	(465,804)	79,281
Net increase (decrease) in cash and cash equivalents	(4,815)	7,551	(206,518)
Cash and cash equivalents, beginning of period	17,118	9,567	216,085
Cash and cash equivalents, end of period	12,303	17,118	9,567
Columbia Property Trust Operating Partnership, L.P.
Cash Flows From Operating Activities:
Net income	12,901	4,216	163,530
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Straight-line rental income	(12,077)	(22,654)	(29,790)
Noncash operating lease expense	836	0	0
Depreciation	67,773	71,934	72,010
Amortization	22,177	28,185	30,376
Impairment loss on real estate assets	43,941	30,812	0
Noncash interest expense	2,562	3,103	3,009
(Gain) loss on extinguishment of debt	0	(23,340)	325
Gains on sales of real estate assets	(42,030)	0	(170,733)
Income from unconsolidated joint ventures	(8,004)	(8,003)	(2,651)
Distributions of earnings from unconsolidated joint ventures	27,977	28,802	3,681
Gain on sale of unconsolidated joint venture interest	0	(762)	0
Changes in Assets and Liabilities, Net of Acquisitions and Dispositions:
Decrease (increase) in tenant receivables, net	918	(2,842)	4,111
Decrease (increase) in prepaid expenses and other assets	(1,662)	7,341	(1,001)
Decrease (increase) in accounts payable and accrued expenses	3,489	(35,708)	(29,032)
Increase (decrease) in deferred income	3,712	(1,919)	(4,056)
Net cash provided by operating activities	122,513	79,165	39,779
Cash Flows From Investing Activities:
Net proceeds from the sale of real estate	375,004	284,608	618,199
Net proceeds from the sale of investments in unconsolidated joint ventures	0	235,083	0
Real estate acquisitions and prepaid transaction costs	(453,128)	(23,034)	(604,769)
Capital improvements and development costs	(65,961)	(65,810)	(53,480)
Deferred lease costs paid	(22,667)	(25,364)	(26,710)
Investments in unconsolidated joint ventures	(17,134)	(38,763)	(369,043)
Distributions in excess of earnings from unconsolidated joint ventures	14,250	13,685	1,985
Net cash provided by (used in) investing activities	(169,636)	380,405	(433,818)
Cash Flows From Financing Activities:
Financing costs paid	(162)	(5,078)	(1,269)
Proceeds from lines of credit and notes payable	802,000	579,000	783,000
Repayments of lines of credit and notes payable	(650,000)	(872,175)	(533,427)
Contributions from Columbia Property Trust	17,663	11,912	296,083
Distributions to Columbia Property Trust	(129,397)	(167,551)	(169,023)
Contribution from noncontrolling interest in consolidated joint venture	5,610	0	0
Net cash provided by (used in) financing activities	45,714	(453,892)	375,364
Net increase (decrease) in cash and cash equivalents	(1,409)	5,678	(18,675)
Cash and cash equivalents, beginning of period	10,931	5,253	23,928
Cash and cash equivalents, end of period	$ 9,522	$ 10,931	$ 5,253

Organization

Organization	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	OrganizationColumbia Property Trust, Inc. ("Columbia Property Trust") (NYSE: CXP) is a Maryland corporation that operates as a real estate investment trust ("REIT") for federal income tax purposes and owns and operates commercial real estate properties. Columbia Property Trust conducts business primarily through Columbia Property Trust Operating Partnership, L.P. ("Columbia OP"), a Delaware limited partnership in which Columbia Property Trust is the general partner and sole owner as of December 31, 2019. Columbia Property Trust acquires, develops, redevelops, owns, leases, and operates real properties directly and through wholly and partially owned subsidiaries and joint ventures. Unless stated otherwise or the context otherwise requires, references to "Columbia Property Trust," "the Company," "we," "us," and "our" shall mean, collectively, Columbia Property Trust, Columbia OP, and the entities consolidated by both Columbia Property Trust and Columbia OP; and references to "Columbia OP" shall mean Columbia OP and the entities consolidated by Columbia OP.As of December 31, 2019, the Company owned 17 operating properties and three properties under development or redevelopment, of which 13 were wholly owned and seven were owned through joint ventures, located primarily in New York, San Francisco, and Washington, D.C. As of December 31, 2019 the operating properties contained a total of 7.3 million rentable square feet and were approximately 97.1% leased.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP"), which require us to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. Columbia Property Trust's consolidated financial statements include the accounts of Columbia Property Trust, Columbia OP, and their consolidated subsidiaries. Columbia OP's consolidated financial statements include the accounts of Columbia OP, and its consolidated subsidiaries. We consolidate any variable interest entity ("VIE") in which we are deemed the primary beneficiary. With respect to entities that are not VIEs, our consolidated financial statements also include the accounts of any entity in which we own a controlling financial interest, and any limited partnership in which we own a controlling general partnership interest. In determining whether Columbia Property Trust or Columbia OP owns a controlling interest, the following factors are considered, among other things: the ownership of voting interests, protective rights, and participatory rights of the investors. All intercompany balances and transactions have been eliminated in consolidation. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the accompanying consolidated financial statements and the accompanying notes. Actual results could differ from those estimates. Fair Value Measurements Columbia Property Trust estimates the fair value of its assets and liabilities (where currently required under GAAP) consistent with the provisions of Accounting Standard Codification 820, Fair Value Measurements ("ASC 820"). Under this standard, fair value is defined as the price that would be received upon sale of an asset or paid upon transfer of a liability in an orderly transaction between market participants at the measurement date. While various techniques and assumptions can be used to estimate fair value depending on the nature of the asset or liability, the accounting standard for fair value measurements and disclosures provides the following fair value technique parameters and hierarchy, depending upon availability: Level 1 – Assets or liabilities for which the identical term is traded on an active exchange, such as publicly traded instruments or futures contracts. Level 2 – Assets and liabilities valued based on observable market data for similar instruments. Level 3 – Assets or liabilities for which significant valuation assumptions are not readily observable in the market. Such assets or liabilities are valued based on the best available data, some of which may be internally developed. Significant assumptions may include risk premiums that a market participant would consider. Real Estate Assets Real estate assets are stated at cost, less accumulated depreciation and amortization. Amounts capitalized to real estate assets consist of the cost of acquisition or construction, and any tenant improvements or major improvements that extend the useful life of the related asset. All repairs and maintenance costs are expensed as incurred. Columbia Property Trust is required to make subjective assessments as to the useful lives of its depreciable assets. To determine the appropriate useful life of an asset, Columbia Property Trust considers the period of future benefit of the asset. These assessments have a direct impact on net income. The estimated useful lives of its assets by class are as follows: Buildings 40 years Building and site improvements 5-25 years Tenant improvements Shorter of economic life or lease term Intangible lease assets Lease term As further described in Note 5, Line of Credit and Notes Payable , Columbia Property Trust capitalizes interest incurred on outstanding debt balances as well as joint venture investments, as appropriate, during development or redevelopment of real estate held directly or in joint ventures. During 2019 and 2018, $5.1 million and $3.8 million of interest was capitalized to construction in progress, respectively; and $1.3 million and $0.2 million of interest was capitalized to investments in unconsolidated joint ventures, respectively. Assets Held for Sale Columbia Property Trust classifies properties as held for sale according to Accounting Standard Codification 360, Accounting for the Impairment or Disposal of Long-Lived Assets ("ASC 360"). According to ASC 360, properties having separately identifiable operations and cash flows, are considered held for sale when the following criteria are met: • Management, having the authority to approve the action, commits to a plan to sell the property. • The property is available for immediate sale in its present condition, subject only to terms that are usual and customary for sales of such property. • An active program to locate a buyer and other actions required to complete the plan to sell the property have been initiated. • The property is being actively marketed for sale at a price that is reasonable in relation to its current fair value. • Actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. • The sale of the property is probable and transfer of the property is expected to qualify for recognition as a completed sale, within one year. At such time that a property is determined to be held for sale, its carrying amount is adjusted to the lower of its depreciated book value or its estimated fair value, less costs to sell, and depreciation is no longer recognized; and assets and liabilities are required to be classified as held for sale on the accompanying consolidated balance sheet. As of December 31, 2019, Cranberry Woods Drive and Pasadena Corporate Park met the aforementioned criteria; thus, these properties are classified as held for sale in the accompanying consolidated balance sheets. The sale of Cranberry Woods closed on January 16, 2020. As of December 31, 2018, none of Columbia Property Trust's properties met the criteria to be classified as held for sale in the accompanying consolidated balance sheet. The major classes of assets and liabilities classified as held for sale are provided below (in thousands): December 31, 2019 Real Estate Assets Held for Sale: Real estate assets, at cost: Land $ 57,117 Buildings and improvements, less accumulated depreciation of $80,543 157,701 Construction in progress 138 Total real estate assets held for sale, net $ 214,956 Other Assets Held for Sale: Tenant receivables $ 156 Straight-line rent receivable 12,591 Prepaid expenses and other assets 334 Deferred lease costs, less accumulated amortization of $10,222 10,836 Total other assets held for sale, net $ 23,917 Liabilities Held for Sale: Accounts payable, accrued expenses, and accrued capital expenditures $ 1,151 Deferred income 1,903 Total liabilities held for sale $ 3,054 Evaluating the Recoverability of Real Estate Assets Columbia Property Trust continually monitors events and changes in circumstances that could indicate that the net carrying amounts of its real estate and related intangible assets and liabilities, of both operating properties and properties under redevelopment, may not be recoverable. When indicators of potential impairment are present that suggest that the net carrying amounts of real estate assets and related intangible assets and liabilities may not be recoverable, Columbia Property Trust assesses the recoverability of these net assets by determining whether the respective carrying values will be recovered through the estimated undiscounted future cash flows expected from the use of the net assets and their eventual disposition. In the event that such expected undiscounted future cash flows do not exceed the carrying values, Columbia Property Trust adjusts the carrying values of the real estate assets and related intangible assets and liabilities to the estimated fair values, pursuant to the property, plant, and equipment accounting standard for the impairment or disposal of long-lived assets, and recognizes an impairment loss. At such time that a property is required to be classified as held for sale, its net carrying amount is adjusted to the lower of its depreciated book value or its estimated fair value, less costs to sell, and depreciation is no longer recognized. Estimated fair values are calculated based on the following hierarchy of information: (i) recently quoted market prices, (ii) market prices for comparable properties, or (iii) the present value of future cash flows, including estimated residual value. Projections of expected future operating cash flows require that Columbia Property Trust estimate future market rental income amounts subsequent to the expiration of current lease agreements, property operating expenses, the number of months it takes to re-lease the property, and the number of years the property is held for investment, among other factors. Due to the inherent subjectivity of the assumptions used to project future cash flows, estimated fair values may differ from the values that would be realized in market transactions. Certain of Columbia Property Trust's assets may be carried at an amount that exceeds that which could be realized in a current disposition transaction. Columbia Property Trust has determined that the carrying values of its real estate assets and related intangible assets are recoverable as of December 31, 2019. In the fourth quarter of 2019, Columbia Property Trust recorded an impairment loss of $20.6 million on Pasadena Corporate Park. Upon deciding to exit the Los Angeles market, Columbia Property Trust began to market for sale its only asset therein, Pasadena Corporate Park, in the fourth quarter of 2019. In January 2020, Columbia Property Trust entered into a contract to sell Pasadena Corporate Park, and anticipates closing on the sale in the first quarter of 2020. As a result, as of December 31,2019, Columbia Property Trust reduced the carrying value of Pasadena Corporate Park to reflect its estimated fair value of $74.5 million, determined based on estimated net sale proceeds (Level 1), by recording an impairment loss of $20.6 million. In the third quarter of 2019, Columbia Property Trust recognized an impairment loss of $23.4 million as a result of changing its holding period expectations for Lindbergh Center in Atlanta, Georgia. Columbia Property Trust entered into a contract to sell Lindbergh Center in the third quarter of 2019, and closed the sale on September 26, 2019. As a result, Columbia Property Trust reduced the carrying value of Lindbergh Center to reflect its estimated fair value, based on the estimated net sale proceeds of $181.0 million (Level 1), by recording an impairment loss of $23.4 million in the third quarter of 2019. In the second quarter of 2018, Columbia Property Trust recognized an impairment loss of $30.8 million in connection with changing the holding period expectations for 222 East 41st Street in New York. Columbia Property Trust widely marketed this property for sale during the second quarter and, as a result, entered into an agreement to sell this property on May 25, 2018 and closed on the sale on May 29, 2018. Upon entering into the sale agreement, Columbia Property Trust reduced 222 East 41st Street's carrying value to reflect its fair value, estimated based on the net contract price of $284.6 million (Level 1), by recording an impairment loss of $30.8 million in the second quarter of 2018. Allocation of Purchase Price of Acquired Assets Upon the acquisition of real properties, Columbia Property Trust allocates the purchase price of properties and related transaction costs to tangible assets, consisting of land, building, site improvements, and identified intangible assets and liabilities, including the value of in-place leases, based in each case on Columbia Property Trust's estimate of their fair values in accordance with ASC 820 (see "Fair Value Measurements" section above for additional details). In conjunction with certain acquisitions, Columbia Property Trust has entered into master lease agreements, which obligate the seller to pay rent pertaining to certain nonrevenue-producing spaces to mitigate the negative effects of lower rental revenues. Columbia Property Trust records payments receivable under such master lease agreements as a reduction of the property basis rather than income. Columbia Property Trust received no proceeds for master leases during 2019, 2018, or 2017. The fair values of the tangible assets of an acquired property (which includes land, building, and site improvements) are determined by valuing the property as if it were vacant, and the "as-if-vacant" value is then allocated to land, building, and site improvements based on management's determination of the relative fair value of these assets. Management determines the as-if-vacant fair value of a property using methods similar to those used by independent appraisers. Factors considered by management in performing these analyses include an estimate of carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases, including leasing commissions and other related costs. In estimating carrying costs, management includes real estate taxes, insurance, and other operating expenses during the expected lease-up periods based on current market demand. Intangible Assets and Liabilities Arising From In-Place Leases Where Columbia Property Trust Is the Lessor As further described below, in-place leases with Columbia Property Trust as the lessor may have values related to direct costs associated with obtaining a new tenant that are avoided for in-place leases, opportunity costs associated with lost rentals that are avoided by acquiring an in-place lease, tenant relationships, and effective contractual rental rates that are above or below market: • Direct costs associated with obtaining a new tenant that are avoided for in-place leases, including commissions, tenant improvement allowances, and other direct costs, are estimated based on management's consideration of current market costs to execute a similar lease. Such direct costs are included in intangible lease origination costs in the accompanying consolidated balance sheets and are amortized to expense over the remaining terms of the respective leases. • The value of opportunity costs associated with lost rentals avoided by acquiring an in-place lease is calculated based on contractual amounts to be paid pursuant to the in-place leases over a market absorption period for a similar lease. Such opportunity costs ("Absorption Period Costs") are included in intangible lease assets in the accompanying consolidated balance sheets and are amortized to expense over the remaining terms of the respective leases. • The value of effective rental rates of in-place leases that are above or below the market rates of comparable leases is calculated based on the present value (using a discount rate that reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be received pursuant to the in-place leases and (ii) management's estimate of fair market lease rates for the corresponding in-place leases. This calculation includes significantly below-market renewal options for which exercise of the renewal option appears to be reasonably assured. These intangible assets or liabilities are measured over the actual or assumed (in the case of renewal options) remaining lease terms. The capitalized above-market and below-market lease values are recorded as intangible lease assets or liabilities and amortized as an adjustment to rental income over the remaining terms of the respective leases. As of December 31, 2019 and 2018, Columbia Property Trust had the following gross intangible in-place lease assets and liabilities (in thousands): Intangible Lease Assets Intangible Intangible Above-Market Absorption December 31, 2019 Gross $ 2,481 $ 117,203 $ 61,702 $ 36,966 Accumulated Amortization (1,202) (57,457) (33,731) (15,127) Net $ 1,279 $ 59,746 $ 27,971 $ 21,839 December 31, 2018 Gross $ 3,174 $ 147,668 $ 99,440 $ 42,847 Accumulated Amortization (1,060) (81,220) (65,348) (21,766) Net $ 2,114 $ 66,448 $ 34,092 $ 21,081 During 2019, 2018, and 2017, Columbia Property Trust recognized the following amortization of intangible lease assets and liabilities (in thousands): Intangible Lease Assets Intangible Intangible Above-Market Absorption For the Years Ended December 31, 2019 $ 288 $ 13,511 $ 7,398 $ 5,395 2018 $ 228 $ 17,137 $ 9,660 $ 6,851 2017 $ 519 $ 16,807 $ 10,124 $ 6,883 The remaining net intangible assets and liabilities as of December 31, 2019, will be amortized as follows (in thousands): Intangible Lease Assets Intangible Intangible Above-Market Absorption For the Years Ending December 31, 2020 $ 172 $ 12,871 $ 5,866 $ 5,483 2021 172 9,328 4,516 3,191 2022 172 7,959 3,429 2,910 2023 172 6,455 2,903 2,336 2024 172 5,594 2,586 1,990 Thereafter 419 17,539 8,671 5,929 $ 1,279 $ 59,746 $ 27,971 $ 21,839 Weighted-average amortization period 6.6 years 5.0 years 4.9 years 5.3 years Intangible Assets and Liabilities Arising From In-Place Leases Where Columbia Property Trust Is the Lessee As of December 31, 2018, Columbia Property Trust had gross below-market lease assets of approximately $32.6 million, net of accumulated amortization of $2.6 million. These below-market lease assets were reclassified to operating lease assets upon adoption of ASC 842, effective January 1, 2019, as described in the "Recent Accounting Pronouncements" section below (see Note 10, Leases , for additional information). Cash and Cash Equivalents Columbia Property Trust considers all highly liquid investments purchased with an original maturity of three Tenant Receivables Tenant receivables consist of rental and reimbursement billings due from tenants. Tenant receivables are recorded at the original amount earned, which approximates fair value. Management assesses the realizability of tenant receivables on an ongoing basis, and, if at any point during the term of a lease it is determined that the collectability of a tenant receivable is not probable, such receivable is written off against lease revenues. During 2019, $22,000 in receivables were written off against lease revenues. Prior to the adoption of ASC 842 on January 1, 2019, Columbia Property Trust recorded an allowance for doubtful accounts when a tenant receivable became uncollectible by recording a provision for doubtful accounts, net of recoveries, in general and administrative – corporate expenses. For 2018, $63,000 of such expenses were recorded to general and administrative – corporate expenses. Straight-Line Rent Receivable Straight-line rent receivable reflects the amount of cumulative adjustments necessary to present rental income on a straight-line basis. Columbia Property Trust recognizes rental revenues on a straight-line basis, ratably over the term of each lease; however, leases often provide for payment terms that differ from the revenue recognized. When the amount of cash billed is less than the amount of revenue recognized, typically early in the lease, straight-line rent receivable is recorded for the difference. The receivable is depleted during periods later in the lease when the amount of cash paid by the tenant is greater than the amount of revenue recognized. Prepaid Expenses and Other Assets Prepaid expenses and other assets primarily include earnest money deposits, escrow accounts held by lenders to pay future real estate taxes, insurance and tenant improvements, notes receivable, nontenant receivables, prepaid taxes, insurance and operating costs, unamortized deferred financing costs related to the line of credit (the "Revolving Credit Facility"), interest rate swaps (when in an asset position), certain corporate assets, and deferred tax assets. Prepaid expenses are recognized over the period to which the good or service relates. Other assets are written off when the asset no longer has future value, or when the company is no longer obligated for the corresponding liability. Deferred Financing Costs Deferred financing costs include costs incurred to secure debt from third-party lenders. Deferred financing costs, except for costs related to the Revolving Credit Facility, are presented as a direct reduction to the carrying amount of the related debt for all periods presented. Deferred financing costs related to the Revolving Credit Facility are included in prepaid expenses and other assets. Columbia Property Trust recognized amortization of deferred financing costs for the years ended December 31, 2019, 2018, and 2017 of approximately $2.4 million, $2.9 million, and $2.8 million, respectively, which is included in interest expense in the accompanying consolidated statements of operations. Deferred Lease Costs Deferred lease costs include costs incurred to procure leases that are paid to third parties or tenants, and incentives that are provided to tenants under the terms of their leases. These costs are capitalized and amortized on a straight-line basis over the terms of the lease. Amortization of third-party leasing costs is reflected as amortization expense, and amortization of lease incentives is reflected as an adjustment to rental income. During 2019, 2018, and 2017, Columbia Property Trust recognized amortization expense for deferred lease costs of $6.3 million, $5.5 million, and $5.2 million, respectively. During 2019, 2018, and 2017, Columbia Property Trust recognized adjustments to rental income for amortization of deferred lease costs of $0.7 million, $2.1 million, and $3.3 million, respectively. Upon receiving notification of a tenant's intention to terminate a lease, unamortized deferred lease costs are amortized over the shortened lease period. Accounts Payable, Accrued Expenses, and Accrued Capital Expenditures Accounts payable, accrued expenses, and accrued capital expenditures primarily include payables related to property operations, capital projects, and interest rate swaps (when in a liability position). Line of Credit and Notes Payable When debt is assumed, Columbia Property Trust records the loan at fair value. The fair value adjustment is amortized to interest expense over the term of the loan using the effective interest method. As described in the "Deferred Financing Costs" section above, line of credit and notes payable is presented on the accompanying consolidated balance sheet net of deferred financing costs related to term loans and notes payable of $2.1 million and $2.7 million as of December 31, 2019 and December 31, 2018, respectively. Bonds Payable Columbia OP has two series of bonds outstanding as of December 31, 2019 and 2018: $350 million of its 10-year unsecured 3.650% senior notes issued at 99.626% of their face value (the "2026 Bonds Payable"); and $350.0 million of its 10-year unsecured 4.150% senior notes issued at 99.859% of their face value (the "2025 Bonds Payable"). The discount on the 2026 Bonds Payable and the 2025 Bonds Payable is amortized to interest expense over the term of the bonds using the effective-interest method. As described in the "Deferred Financing Costs" section above, bonds payable are presented on the accompanying consolidated balance sheet net of deferred financing costs related to bonds payable of $3.6 million and $4.2 million as of December 31, 2019 and December 31, 2018, respectively. Common Stock Repurchase Program Columbia Property Trust is authorized to repurchase shares of its common stock, par value $0.01 per share, subject to certain limitations. As of December 31, 2019, $166.5 million remains available for repurchases under the current stock repurchase program. See Note 8, Stockholders' Equity and Partner's Capital , for additional details. Common stock repurchases are charged against equity as incurred, and the repurchased shares are retired. Preferred Stock Columbia Property Trust is authorized to issue up to 100.0 million shares of one or more classes or series of preferred stock with a par value of $0.01 per share. Columbia Property Trust's board of directors may determine the relative rights, preferences, and privileges of each class or series of preferred stock issued, which may be more beneficial than the rights, preferences, and privileges attributable to Columbia Property Trust's common stock. To date, Columbia Property Trust has not issued any shares of preferred stock. Common Stock The par value of Columbia Property Trust's issued and outstanding shares of common stock is classified as common stock, with the remainder allocated to additional paid-in capital. Distributions To maintain its status as a REIT, Columbia Property Trust is required by the Internal Revenue Code of 1986, as amended (the "Code"), to make distributions to stockholders each taxable year equal to at least 90% of its REIT taxable income, computed without regard to the dividends-paid deduction and by excluding net capital gains attributable to stockholders ("REIT taxable income"). To the extent that Columbia Property Trust satisfies the distribution requirement but distributes less than 100% of its REIT taxable income, Columbia Property Trust would be subject to federal and state corporate income tax on the undistributed income. Distributions to the stockholders are determined by the board of directors of Columbia Property Trust and are dependent upon a number of factors relating to Columbia Property Trust, including funds available for payment of distributions, financial condition, the timing of property acquisitions, capital expenditure requirements, and annual distribution requirements in order to maintain Columbia Property Trust's status as a REIT under the Code. Noncontrolling Interests Noncontrolling interests represent the equity interests of a consolidated joint venture that are not owned by Columbia Property Trust. Noncontrolling interests are adjusted for contributions, distributions, and earnings attributable to the noncontrolling interest holders of the consolidated joint venture. Earnings are allocated to joint venture partners using the hypothetical liquidation at book value method, based on the terms of the respective joint venture agreements, and are recorded as net income (loss) attributable to noncontrolling interests in the accompanying consolidated statements of operations. For 2019, all of Columbia Property Trust's noncontrolling interests relate to 101 Franklin Street, which was acquired on December 2, 2019. For additional information, see Note 3, Real Estate Transactions . Interest Rate Swap Agreements Columbia Property Trust enters into interest rate swap contracts to mitigate its interest rate risk on the related financial instruments. Columbia Property Trust does not enter into derivative or interest rate transactions for speculative purposes and currently does not have any derivatives that are not designated as hedges; however, certain of its derivatives may, at times, not qualify for hedge accounting treatment. Columbia Property Trust records the fair value of its interest rate swaps on its consolidated balance sheet either as prepaid expenses and other assets or as accounts payable, accrued expenses, and accrued capital expenditures. Changes in the fair value of interest rate swaps that are designated as cash flow hedges are recorded as other comprehensive income (loss). Changes in the fair value of interest rate swaps that do not qualify for hedge accounting treatment are recorded as gain or loss on interest rate swaps. Amounts received or paid under interest rate swap agreements are recorded as interest expense for contracts that qualify for hedge accounting treatment and as loss on interest rate swaps for contracts that do not qualify for hedge accounting treatment. As of December 31, 2019, Columbia Property Trust has two interest rate swaps, with an aggregate notional amount of $450.0 million. The following tables provide additional information related to Columbia Property Trust's interest rate swaps as of December 31, 2019 and 2018 (in thousands): Estimated Fair Value as of Instrument Type Balance Sheet Classification 2019 2018 Derivatives Designated as Hedging Instruments: Interest rate contracts Prepaid expenses and other assets $ 551 $ 2,344 Interest rate contracts Accounts payable $ 1,652 $ — As a result of the interest rate contract in the above table, Columbia Property Trust estimates recognizing a reduction in interest expense of approximately $0.9 million over the next 12 months. Columbia Property Trust applied the provisions of ASC 820 in recording its interest rate swaps at fair value. The fair values of the interest rate swaps, classified under Level 2, were determined using a third-party proprietary model that is based on prevailing market data for contracts with matching durations, current and anticipated London Interbank Offered Rate ("LIBOR") information, and reasonable estimates about relevant future market conditions. Columbia Property Trust has determined that the fair value, as determined by the third party, is reasonable. Years Ended December 31, 2019 2018 2017 Market value adjustment to interest rate swaps designated as hedging instruments and included in other comprehensive income (loss) $ (3,445) $ 1,441 $ 1,786 Revenue Recognition The majority of Columbia Property Trust’s revenues are derived from leases and are reflected as lease revenues on the accompanying consolidated statements of operations. For more information about Columbia Property Trust's lease revenue streams see Note 10, Leases . In determining when to begin recognizing rental revenues, Columbia Property Trust considers a number of factors, including the nature of the physical improvements made in connection with the lease. When Columbia Property Trust owns the improvements for accounting purposes, revenue recognition generally begins once the improvements are substantially complete and the lessee has taken possession of the improved space. When Columbia Property Trust does not own the improvements for accounting purposes (the lessee is the owner), revenue recognition generally begins once the lessee takes possession of the unimproved space; in these instances, the tenant allowance is accounted for as a lease incentive, which reduces rental revenues over the lease term. When evaluating which party (lessee or lessor) owns the improvements for accounting purposes, Columbia Property Trust considers a number of factors, including, among other things: whether the lease stipulates what the tenant allowance may be used for; whether the lessee or lessor retains legal title to the improvements; the expected economic life of the improvements relative to the lease term; and who directs the construction of the improvements. The determination of who owns the improvements for accounting purposes is subject to significant judgement and is not based on any one factor. For information about Columbia Property Trust's other revenue streams, please see Note 11, Non-Lease Revenues. Income Taxes Columbia Property Trust has elected to be taxed as a REIT under the Code, as amended (the "Code") and has operated as such beginning with its taxable year ended December 31, 2003. To qualify as a REIT, Columbia Property Trust must meet certain organizational and operational requirements, including a requirement to distribute at least 90% of its REIT taxable income, as defined by the Code, to its stockholders. To the extent that Columbia Property Trust satisfies the distribution requirement but distributes less than 100% of its REIT taxable income, Columbia Property Trust would be subject to federal and state corporate income tax on the undistributed income. Generally, Columbia Property Trust does not incur federal income taxes, other than as described in the following paragraph, because its stockholder distributions typically exceed its taxable income due to noncash expenses such as depreciation. Columbia Property Trust is, however, subject to certain state and local taxes related to the operations of properties in certain locations, which have been provided for in the accompanying consolidated financial stateme

Real Estate Transactions

Real Estate Transactions	12 Months Ended
	Dec. 31, 2019
Business Acquisitions and Dispositions [Abstract]
Real Estate Transactions	Real Estate Transactions Acquisitions During 2019, 2018, and 2017, Columbia Property Trust acquired the following properties: Property Location Date Percent Acquired Purchase Price (in thousands) (1) 2019 201 California Street San Francisco, CA December 9, 2019 100.0 % $ 238,900 101 Franklin Street (2) New York, NY December 2, 2019 92.5 % $ 205,500 2018 Lindbergh Center – Retail Atlanta, GA October 24, 2018 100.0 % $ 23,000 799 Broadway New York, NY October 3, 2018 49.7 % $ 30,200 (3) 2017 149 Madison Avenue New York, NY November 28, 2017 100.0 % $ 87,700 1800 M Street Washington, D.C. October 11, 2017 55.0 % $ 231,550 (3) 249 West 17th Street & 218 West 18th Street New York, NY October 11, 2017 100.0 % $ 514,100 114 Fifth Avenue New York, NY July 6, 2017 49.5 % $ 108,900 (3) (1) Exclusive of transaction costs and price adjustments. See purchase price allocation table below for a breakout of the net purchase price for wholly owned properties. (2) Property is owned through a consolidated joint venture. (3) These properties are owned through unconsolidated joint ventures. Purchase price is for Columbia Property Trust's partial interests in the properties. 201 California Street On December 9, 2019, Columbia Property Trust acquired 201 California Street, a 17-story, 252,000-square-foot office tower in San Francisco. As of the acquisition date, 201 California Street was 99% leased to 34 tenants, including First Republic Bank (13%), Dow Jones & Company, Inc. (12%), and Cooper, White & Cooper, LLP (12%). For the period from December 9, 2019 to December 31, 2019, Columbia Property Trust recognized revenues of $1.4 million and net income of $0.1 million from 201 California Street. 101 Franklin Street On December 2, 2019, Columbia Property Trust acquired a 92.5% controlling financial interest in 101 Franklin Street (formerly 250 Church Street), a 16-story, 235,000-square-foot office building in Manhattan that will be fully redeveloped through a consolidated joint venture with an affiliate of Normandy (see Note 16, Subsequent Event ). During 2019, Columbia Property Trust earned $37,000 from its investment in 101 Franklin Street. Lindbergh Center – Retail On October 24, 2018, Columbia Property Trust acquired the 147,000 square feet of ancillary retail and office space surrounding its existing property, Lindbergh Center, for a gross purchase price of $23.0 million. Lindbergh Center – Retail was sold in the Lindbergh Center disposition, as described below. 799 Broadway Joint Venture On October 3, 2018, Columbia Property Trust formed a joint venture with an affiliate of Normandy (see Note 16, Subsequent Event ) for the purpose of developing a 12-story, 182,000-square-foot office building at 799 Broadway in New York (the "799 Broadway Joint Venture"). Columbia Property Trust made an initial equity contribution of $30.2 million in the 799 Broadway Joint Venture for a 49.7% interest therein. At inception, the 799 Broadway Joint Venture acquired the property located at 799 Broadway for $145.5 million, exclusive of transaction costs and development costs, and borrowed $97.0 million under a construction loan with total capacity of $187.0 million. 149 Madison Avenue 149 Madison Avenue is a 12-story, 127,000-square-foot office building, which was vacant at the time of acquisition. Columbia Property Trust acquired 149 Madison Avenue subject to a ground lease which expired in January 2018. Columbia Property Trust is redeveloping this property. For the period from November 28, 2017 to December 31, 2017, Columbia Property Trust recognized $10,300 of revenues and net income of $9,200 from 149 Madison Avenue. All of the office space at 149 Madison Avenue is leased to WeWork. 1800 M Street Joint Venture Columbia Property Trust entered a new joint venture partnership with Allianz Real Estate of America LLC ("Allianz"), which simultaneously acquired 1800 M Street, a 10-story, 581,000-square-foot office building in Washington, D.C. that is 94% leased, for a total of $421.0 million (the "1800 M Street Joint Venture"). Columbia Property Trust owns a 55% interest in the 1800 M Street Joint Venture, and Allianz owns the remaining 45%. 249 West 17th Street & 218 West 18th Street 249 West 17th Street is made up of two interconnected 12- and six-story towers, totaling 281,000 square feet of office and retail space, and 218 West 18th Street is a 12-story, 166,000-square-foot office building. As of the acquisition date, 249 West 17th Street was 100% leased to four tenants, including Twitter, Inc. (76%) and Room & Board, Inc. (21%); and, as of the acquisition date, 218 West 18th Street was 100% leased to seven tenants, including Red Bull North America, Inc. (25%), Company 3 (18%), SY Partners (16%), and SAE (16%). For the period from October 11, 2017 to December 31, 2017, Columbia Property Trust recognized revenues of $5.9 million and net income of $1.8 million from 249 West 17th Street, and revenues of $3.0 million and net income of $0.8 million from 218 West 18th Street. 114 Fifth Avenue Joint Venture Columbia Property Trust acquired a 49.5% equity interest in a joint venture that owns the 114 Fifth Avenue property from Allianz (the "114 Fifth Avenue Joint Venture"). 114 Fifth Avenue is a 19-story, 352,000-square-foot building located in Manhattan's Flatiron District that is 100% leased, and is unencumbered by debt. The 114 Fifth Avenue Joint Venture is owned by Columbia Property Trust (49.5%), Allianz (49.5%), and L&L Holding Company (1.0%). Purchase Price Allocations for Consolidated Property Acquisitions 201 California Street 101 Franklin Street (1) 149 Madison Avenue 249 West 17th Street 218 West 18th Street Location San Francisco, CA New York, NY New York, NY New York, NY New York, NY Date Acquired December 9, 2019 December 2, 2019 November 28, 2017 October 11, 2017 October 11, 2017 Purchase Price: Land $ 77,833 $ 57,145 $ 59,112 $ 113,149 $ 43,836 Building and improvements 157,513 149,500 28,989 194,109 126,957 Intangible lease assets 13,241 — — 27,408 12,120 Intangible lease origination costs 5,785 — — 13,062 4,168 Intangible below market lease liability (8,064) — — (7,131) (11,757) Total purchase price $ 246,308 $ 206,645 $ 88,101 $ 340,597 $ 175,324 (1) Owned through a consolidated joint venture, in which Columbia Property Trust owns a 92.5% interest. Note 2, Summary of Significant Accounting Policies , provides a discussion of the estimated useful life for each asset class. Pro Forma Financial Information The following unaudited pro forma statements of operations presented for 2019, 2018, and 2017, have been prepared for Columbia Property Trust to give effect to the acquisitions of 201 California Street and 101 Franklin Street as if the acquisitions had occurred on January 1, 2018; and 249 West 17th Street, 218 West 18th Street, and 149 Madison Avenue as if the acquisitions had occurred on January 1, 2016. The following unaudited pro forma financial results for Columbia Property Trust have been prepared for informational purposes only and are not necessarily indicative of future results or of actual results that would have been achieved had these acquisitions been consummated as of January 1, 2018 and January 1, 2016 (in thousands): 2019 2018 2017 Revenues $ 304,756 $ 312,003 $ 319,064 Net income attributable to common stockholders of Columbia Property Trust $ 17,600 $ 16,822 $ 183,318 Dispositions During 2019, 2018, and 2017, Columbia Property Trust sold the following properties and partial interest in properties of unconsolidated joint ventures. Additional information for certain of the dispositions is provided below the table. Property Location Date % Sold Sale Price (1) (in thousands) Gain on Sale 2019 Lindbergh Center Atlanta, GA September 26, 2019 100.0 % $ 187,000 $ — One & Three Glenlake Parkway Atlanta, GA April 15, 2019 100.0 % $ 227,500 $ 42,030 2018 222 East 41st Street New York, NY May 29, 2018 100.0 % $ 332,500 $ — 263 Shuman Boulevard Chicago, IL April 13, 2018 100.0 % $ 49,000 $ 24,039 University Circle & San Francisco, CA February 1, 2018 22.5 % $ 235,300 (2) $ 762 2017 University Circle & 333 Market Street San Francisco, CA July 6, 2017 22.5 % $ 234,000 (2) $ 102,365 Key Center Tower & Marriott Cleveland, OH January 31, 2017 100.0 % $ 267,500 $ 9,466 Houston Properties Houston, TX January 6, 2017 100.0 % $ 272,000 $ 63,688 (1) Exclusive of transaction costs and price adjustments. (2) Sales price is for the partial interests in the properties or joint ventures that were sold. Lindbergh Center On September 26, 2019, Columbia Property Trust closed on the sale of Lindbergh Center, including Lindbergh Center – Retail, for a gross sales price of $187.0 million, exclusive of transaction costs. Columbia Property Trust recognized an impairment loss of $23.4 million related to this property in the third quarter of 2019, as further described in Note 2, Summary of Significant Accounting Policies . $46.0 million of the proceeds from this transaction were used to pay down the Revolving Credit Facility, as described in Note 5, Line of Credit and Notes Payable . One & Three Glenlake Parkway On April 15, 2019, Columbia Property Trust closed on the sale of One & Three Glenlake Parkway in Atlanta, for a gross sale price of $227.5 million, exclusive of $33.6 million of adjustments for tenant improvement allowances and rent abatements funded at closing. The proceeds from this transaction were used to pay down the Revolving Credit Facility, as described in Note 5, Line of Credit and Notes Payable . 222 East 41st Street On May 29, 2018, Columbia Property Trust closed on the sale of 222 East 41st Street in New York, for $332.5 million, exclusive of transaction costs. Columbia Property Trust recognized an impairment loss of $30.8 million related to this property in the second quarter of 2018, as further described in Note 2, Summary of Significant Accounting Policies . The proceeds from this transaction were used to fully repay the $180.0 million remaining balance on a $300 million bridge loan, as described in Note 5, Line of Credit and Notes Payable . 263 Shuman Boulevard On April 13, 2018, Columbia Property Trust transferred 263 Shuman Boulevard to the lender in extinguishment of the loan principal of $49.0 million, accrued interest expense, and accrued property operating costs, which resulted in a gain on extinguishment of debt of $24.0 million in the second quarter of 2018. University Circle & 333 Market Street On July 6, 2017, Columbia Property Trust contributed 333 Market Street and the University Circle to joint ventures, and simultaneously sold a 22.5% interest in those joint ventures for $234.0 million to Allianz, an unrelated third party (collectively, the "San Francisco Joint Ventures"). On February 1, 2018, as agreed at the time of the initial San Francisco Joint Ventures formation, Allianz acquired another 22.5% interest in each of the San Francisco Joint Ventures at an aggregate price of $235.3 million, thereby reducing Columbia Property Trust's equity interest in each joint venture to 55.0%. These proceeds were used to reduce the balance on a $300 million bridge loan and the Revolving Credit Facility, as described in Note 5, Line of Credit and Notes Payable . Key Center Tower & Marriott Key Center Tower & Marriott were sold in one transaction for $254.5 million of gross proceeds at closing and a $13.0 million, 10-year accruing note receivable from the principal of the buyer. As a result, Columbia Property Trust has applied the installment method to account for this transaction, and deferred $13.0 million of the total $22.5 million gain on sale. Houston Property Sale

Unconsolidated Joint Ventures

Unconsolidated Joint Ventures	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Unconsolidated Joint Ventures	Joint Ventures As of December 31, 2019 and December 31, 2018, Columbia OP owns interests in the following properties through joint ventures, which are accounted for using the equity method of accounting: Geographic Market Ownership Interest Carrying Value of Investment (1) Joint Venture Property Name December 31, 2019 December 31, 2018 Market Square Joint Venture Market Square Washington, D.C. 51.0 % $ 135,557 $ 134,250 University Circle Joint Venture University Circle San Francisco 55.0 % 283,633 292,951 333 Market Street Joint Venture 333 Market Street San Francisco 55.0 % 269,638 273,783 114 Fifth Avenue Joint Venture 114 Fifth Avenue New York 49.5 % 87,750 99,283 1800 M Street Joint Venture 1800 M Street Washington, D.C. 55.0 % 233,196 237,333 799 Broadway Joint Venture (2) 799 Broadway New York 49.7 % 44,686 (4) 33,753 $ 1,054,460 $ 1,071,353 (1) Includes basis differences. Columbia Property Trust's investments in unconsolidated joint ventures were greater than the historical costs recorded at the underlying joint venture level by $279.2 million and $282.0 million as of December 31, 2019 and December 31, 2018, respectively. Such basis differences result from the timing of each partner's joint venture interest acquisition; and formation costs incurred by Columbia Property Trust. Basis differences are amortized to income (loss) from unconsolidated joint ventures over the lives of the underlying assets or liabilities. (2) Columbia Property Trust capitalized interest of $1.3 million and $0.2 million on its investment in the 799 Broadway Joint Venture in 2019 and 2018, respectively. Columbia Property Trust has determined that none of its unconsolidated joint ventures are variable interest entities. However, Columbia Property Trust and its unconsolidated joint venture partners have substantive participation rights in the joint ventures, including management selection and termination, and the approval of operating and capital decisions. As such, Columbia Property Trust uses the equity method of accounting to record its investment in these joint ventures. Under the equity method, the investment in the joint ventures is recorded at cost and adjusted for cash contributions and distributions, and allocations of income or loss. Columbia Property Trust evaluates the recoverability of its investments in unconsolidated joint ventures in accordance with accounting standards for equity investments by first reviewing the investment for any indicators of impairment. If indicators are present, Columbia Property Trust estimates the fair value of the investment. If the carrying value of the investment is greater than the estimated fair value, management makes an assessment of whether the impairment is "other-than-temporary." In making this assessment, management considers the following: (1) the length of time and the extent to which fair value has been less than cost, and (2) Columbia Property Trust's intent and ability to retain its interest long enough for a recovery in market value. Based on the assessment as described above, Columbia Property Trust has determined that none of its investments in joint ventures are other-than-temporarily impaired as of December 31, 2019. Condensed Combined Financial Information Summarized balance sheet information for each of the unconsolidated joint ventures is as follows (in thousands): Total Assets Total Debt Total Equity (1) December 31, 2019 December 31, 2018 December 31, 2019 December 31, 2018 December 31, 2019 December 31, 2018 Market Square Joint Venture $ 582,747 $ 582,176 $ 324,815 (2) $ 324,762 $ 241,719 $ 241,581 University Circle Joint Venture 216,546 224,746 — — 212,656 219,390 333 Market Street Joint Venture 367,652 375,884 — — 352,385 360,915 114 Fifth Avenue Joint Venture 485,442 377,970 — — 127,554 149,243 1800 M Street Joint Venture 437,439 447,585 — — 421,588 429,016 799 Broadway Joint Venture 201,210 168,390 109,735 (3) 95,630 85,316 67,189 $ 2,291,036 $ 2,176,751 $ 434,550 $ 420,392 $ 1,441,218 $ 1,467,334 (1) Excludes basis differences (see footnote (1) to the Carrying Value of Investment table above). (2) The Market Square Joint Venture has a mortgage note with an outstanding balance of $325.0 million as of December 31, 2019 and December 31, 2018. The Market Square mortgage note bears interest at 5.07% and matures on July 1, 2023. (3) Reflects $113.2 million outstanding, net of $3.5 million of net unamortized deferred financing costs, on the 799 Broadway construction loan. The 799 Broadway construction loan is being used to finance a portion of the 799 Broadway development project, has total capacity of $187.0 million, and bears interest at LIBOR, capped at 4.00%, plus a spread of 425 basis points (the "Construction Loan"). A portion of the monthly interest payments accrue into the balance of the loan. The Construction Loan matures on October 9, 2021, with two one Commitments and Contingencies . Summarized income statement information for the unconsolidated joint ventures for the years ended December 31, 2019, 2018, and 2017 is as follows (in thousands): Total Revenues Net Income (Loss) Columbia Property Trust's Share of Net Income (Loss) (1) 2019 2018 2017 2019 2018 2017 2019 2018 2017 Market Square Joint Venture $ 47,737 $ 44,815 $ 41,749 $ (11,515) $ (12,304) $ (15,192) $ (5,873) $ (6,275) $ (7,747) University Circle Joint Venture 44,427 43,581 19,386 24,251 23,776 9,826 13,338 13,478 7,561 333 Market Street Joint Venture 28,170 27,006 12,971 14,929 14,620 6,948 8,211 8,312 5,331 114 Fifth Avenue Joint Venture 42,921 41,169 20,133 (10,674) (10,256) (4,885) (5,283) (5,077) (2,820) 1800 M Street Joint Venture 38,377 37,486 8,005 4,887 4,239 619 2,688 2,332 326 799 Broadway Joint Venture — — — (882) (132) — (439) (66) — $ 201,632 $ 194,057 $ 102,244 $ 20,996 $ 19,943 $ (2,684) $ 12,642 $ 12,704 $ 2,651 (1) Excludes amortization of basis differences, as described in footnote (1) to the carrying value of investment table above, which are recorded as income (loss) from unconsolidated joint ventures in the accompanying consolidated statements of operations. Asset and Property Management Fees Columbia Property Trust provides property and asset management services to the Market Square Joint Venture, the University Circle Joint Venture , the 333 Market Street Joint Venture, and the 1800 M Street Joint Venture. Under these agreements, Columbia Property Trust oversees the day-to-day operations of these joint ventures and their properties, including property management, property accounting, and other administrative services. During the years ended December 31, 2019, 2018, and 2017, Columbia Property Trust earned the following fees from these unconsolidated joint ventures (in thousands): 2019 2018 2017 Market Square Joint Venture $ 2,256 $ 2,156 $ 1,998 University Circle Joint Venture 2,313 2,283 1,000 333 Market Street Joint Venture 819 784 367 1800 M Street Joint Venture 2,156 2,161 417 $ 7,544 $ 7,384 $ 3,782 Columbia Property Trust also received reimbursements of property operating costs of $4.3 million, $4.2 million, and $2.0 million for the years ended December 31, 2019, 2018, and 2017, respectively, which are included in other property income revenues in the accompanying consolidated statements of operations. Property management fees of $0.6 million and $0.7 million, respectively, were due to Columbia Property Trust from the joint ventures and are included in prepaid expenses and other assets on the accompanying consolidated balance sheets as of December 31, 2019 and December 31, 2018, respectively.

Line of Credit and Notes Payabl

Line of Credit and Notes Payable	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Line of Credit and Notes Payable	Line of Credit and Notes Payable Columbia OP is the borrower on all of Columbia Property Trust's outstanding debt. As of December 31, 2019 and 2018, Columbia Property Trust had the following line of credit and notes payable indebtedness outstanding (excluding bonds payable; see Note 6, Bonds Payable ) in thousands: Rate as of Term Debt or Interest Only Outstanding Balance as of Facility Maturity 2019 2018 Revolving Credit Facility LIBOR + 90 bp (1) Interest only January 31, 2023 $ 334,000 $ 482,000 $300 Million Term Loan LIBOR + 100 bp (2) Interest only January 31, 2024 300,000 — $150 Million Term Loan LIBOR + 110 bp (3) Interest only July 29, 2022 150,000 150,000 Less: Deferred financing costs related to term loans (2,084) (2,692) Total indebtedness $ 781,916 $ 629,308 (1) As of December 31, 2019, borrowings under the Revolving Credit Facility, as described below, bear interest at the option of Columbia Property Trust at an alternate base rate, plus an applicable margin ranging from 0.00% to 0.45% for base-rate borrowings, or at LIBOR, as defined in the credit agreement, plus an applicable margin ranging from 0.775% to 1.45% for LIBOR-based borrowings, based on Columbia Property Trust's applicable credit rating. (2) Columbia Property Trust is party to an interest rate swap agreement with a notional amount of $300.0 million, which effectively fixes its interest rate on the $300 Million Term Loan, as further described below, at 2.55% and terminates on August 13, 2024. This interest rate swap agreement qualifies for hedge accounting treatment; therefore, changes in the fair value are recorded as a market value adjustment to interest rate swap in the accompanying consolidated statement of other comprehensive income. (3) Columbia Property Trust is party to an interest rate swap agreement with a notional amount of $150.0 million, which effectively fixes its interest rate on the $150 Million Term Loan, as further described below, at 3.07% and terminates on July 29, 2022. This interest rate swap agreement qualifies for hedge accounting treatment; therefore, changes in fair value are recorded as a market value adjustment to interest rate swap in the accompanying consolidated statement of other comprehensive income. Term Loan and Line of Credit Amendment and Restatement On December 7, 2018, Columbia Property Trust amended and restated its $500.0 million revolving credit facility and $300.0 million unsecured term loan (together, the "Credit Agreement"). The Credit Agreement provides for (i) a $650.0 million unsecured revolving credit facility (the "Revolving Credit Facility"), with an initial term ending January 31, 2023 and two six At Columbia Property Trust's option, borrowings under the Credit Agreement bear interest at either (i) the alternate base rate plus an applicable margin based on five stated pricing levels ranging from 0.00% to 0.45% for the Revolving Credit Facility and 0.00% to 0.65% for the $300 Million Term Loan, or (ii) the LIBOR rate, as defined in the credit agreement, plus an applicable margin based on five stated pricing levels ranging from 0.775% to 1.45% for the Revolving Credit Facility and 0.85% to 1.65% for the $300 Million Term Loan, in each case based on Columbia Property Trust's credit rating. As described above, the interest rate on the $300 Million Term Loan has been effectively fixed at 2.55% with an interest rate swap agreement. Debt Covenants As of December 31, 2019, the $300 Million Term Loan, the $150 Million Term Loan, and the Revolving Credit Facility (collectively, the "Debt Facilities") contain representations and warranties, financial and other affirmative and negative covenants, events of defaults, and remedies typical for these types of facilities. The financial covenants as defined in the Debt Facilities: • limit the ratio of secured debt to total asset value to 40% or less; • require the fixed charge coverage ratio to be at least 1.50:1.00; • limit the ratio of debt to total asset value to 60% or less, or 65% or less following a material transaction; • require the unencumbered interest coverage ratio to be at least 1.75:1.00; and • limit the unencumbered leverage ratio to 60% or less, or 65% or less following a material transaction. As of December 31, 2019, Columbia Property Trust was in compliance with the restrictive financial covenants on its Debt Facilities and notes payable obligations. Fair Value of Debt The estimated fair value of Columbia Property Trust's consolidated line of credit and notes payable as of December 31, 2019 and 2018, was approximately $784.1 million and $632.1 million, respectively. The related carrying value of the line of credit and notes payable as of December 31, 2019 and 2018, was $784.0 million and $632.0 million, respectively. Columbia Property Trust estimated the fair value of its Revolving Credit Facility and term loans by obtaining estimates for similar facilities from multiple market participants as of the respective reporting dates. Therefore, the fair values determined are considered to be based on observable market data for similar instruments (Level 2). Interest Paid and Capitalized As of December 31, 2019 and 2018, Columbia Property Trust's weighted-average interest rate on its consolidated line of credit and notes payable was approximately 2.63% and 3.26%, respectively. Columbia Property Trust made interest payments of approximately $17.9 million, $22.1 million, and $21.5 million during 2019, 2018, and 2017, respectively. Columbia Property Trust capitalizes interest on development, redevelopment, and improvement projects owned directly and through joint ventures, using the weighted-average interest rate of its consolidated borrowings for the period. During 2019, 2018, and 2017, Columbia Property Trust capitalized interest of $5.1 million, $4.0 million, and $0.3 million, respectively. For 2019, the weighted average interest rate on Columbia Property Trust's outstanding borrowings was 3.55%. Debt Repayments and Extinguishment There were no debt repayments in 2019. During 2018 Columbia Property Trust made the following debt repayments: • On December 7, 2018, concurrent with closing on the Credit Agreement, Columbia Property Trust repaid the $300.0 million remaining balance on the $300 Million Term Loan, which, as described above, includes a delayed-draw feature, allowing up to 12 months to fully draw the term loan. • On October 10, 2018, Columbia Property Trust repaid the $20.7 million outstanding balance on the One Glenlake mortgage note two months prior to its original maturity date. • On April 13, 2018, Columbia Property Trust transferred 263 Shuman Boulevard to the lender in extinguishment of the $49.0 million loan principal, accrued interest expense, and accrued property operating expenses, which resulted in a gain on extinguishment of debt of $24.0 million in the second quarter of 2018. • On February 2, 2018, Columbia Property Trust repaid $120.0 million of the outstanding balance on a $300.0 million bridge loan, using a portion of the proceeds from the sale of an interest in the San Francisco Joint Ventures, as described in Note 3, Real Estate Transactions . On May 30, 2018, Columbia Property Trust repaid the remaining $180.0 million outstanding balance on the bridge loan, using a portion of the proceeds from the sale of 222 East 41st Street, as described in Note 3, Real Estate Transactions . As a result, Columbia Property Trust has recognized a loss on extinguishment of debt of $0.3 million related to unamortized deferred financing costs. The following table summarizes the aggregate maturities of Columbia Property Trust's line of credit and notes payable as of December 31, 2019 (in thousands): 2020 $ — 2021 — 2022 150,000 2023 334,000 2024 300,000 Thereafter — Total $ 784,000

Bonds Payable

Bonds Payable	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Bonds Payable	Bonds Payable Columbia OP has two series of bonds outstanding as of December 31, 2019 and 2018: $350 million of 10-year, unsecured 3.650% senior notes issued at 99.626% of their face value (the "2026 Bonds Payable"); and $350.0 million of 10-year, unsecured 4.150% senior notes issued at 99.859% of their face value (the "2025 Bonds Payable"). Both series of bonds are guaranteed by Columbia Property Trust and require semi-annual interest payments. Upon issuance, a portion of the 2026 Bonds Payable was used to redeem $250.0 million of bonds payable, due in April 2018. During the years ended December 31, 2019 and 2018, Columbia Property Trust made interest payments of $27.3 million on its bonds payable. The principal amount of the 2026 Bonds Payable is due and payable on August 15, 2026, and the principal amount of the 2025 Bonds Payable is due and payable on April 1, 2025. The 2026 Bonds Payable and the 2025 Bonds Payable contain certain restrictive covenants. These covenants, as defined, pursuant to an indenture: • limit the ratio of debt to total assets to 60%; • limit Columbia Property Trust's ability to incur debt if the consolidated income available for debt service to annual debt service charge for four previous consecutive fiscal quarters is less than 1.50:1.00 on a pro forma basis; • limit Columbia Property Trust's ability to incur liens if, on an aggregate basis for Columbia Property Trust, the secured debt amount would exceed 40% of the value of the total assets; and • require that the ratio of unencumbered asset value, as defined, to total unsecured debt be at least 150% at all times. As of December 31, 2019, Columbia Property Trust was in compliance with the restrictive financial covenants on its 2026 Bonds Payable and 2025 Bonds Payable. The estimated fair value of the 2025 Bonds Payable and the 2026 Bonds Payable as of December 31, 2019 and 2018, was approximately $734.4 million and $685.0 million, respectively. The related carrying value of the bonds payable, net of discounts, as of December 31, 2019 and 2018, was $698.9 million and $698.7 million, respectively. Columbia Property Trust estimated the fair value of the bonds payable based on a discounted cash flow analysis, using observable market data for its bonds payable and similar instruments (Level 2). The discounted cash flow method of assessing fair value results in a general approximation of value, which may differ from the price that could be achieved in a market transaction.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments Under Existing Lease Agreements Certain lease agreements include provisions that, at the option of the tenant, may obligate Columbia Property Trust to expend capital to expand an existing property or provide other expenditures for the benefit of the tenant. As of December 31, 2019, Columbia Property Trust had the following material tenant obligations which have arisen in the normal course of business: $17.5 million related to the WeWork lease at 149 Madison and $17.9 million related to the Pershing lease at 95 Columbus. Such amounts are payable as incurred, and therefore no accrual is booked as of December 31, 2019. Additionally, in January 2020, Columbia Property Trust preleased space to be added to 80 M Street in a vertical expansion project. Columbia is required to fund approximately $70.0 million related to construction and tenant improvement allowances for the new space. Commitments Under Unconsolidated Joint Venture Agreements Columbia Property Trust's joint venture agreements, including those that are developing or redeveloping properties, provide for capital contributions to be made to the joint ventures by the joint venture partners. As of December 31, 2019, Columbia Property Trust holds seven properties through consolidated and unconsolidated joint ventures, including three that are under development or redevelopment. Capital contributions are payable when a capital call is made by the joint venture, and there are no unfunded capital calls as of December 31, 2019. Columbia Property Trust guarantees a portion of the debt held by the 799 Broadway Joint Venture. As of December 31, 2019, the 799 Broadway Joint Venture has $113.2 million in outstanding borrowings on the Construction Loan, as further described in Note 4, Unconsolidated Joint Ventures . Pursuant to a joint and several guaranty agreement with the Construction Loan lender, Columbia Property Trust and Normandy are required to make aggregate additional equity contributions to the joint venture based on the initial expected project costs, less the amount of equity contributions made to date. As of December 31, 2019, the remaining equity contribution requirement is $31.9 million, of which $15.8 million reflects Columbia Property Trust's allocated share. Equity contributions become payable by Columbia Property Trust to the joint venture when a capital call is received. As of December 31, 2018, no capital calls remain unpaid; therefore, no liability has been recorded related to this guaranty. Litigation Columbia Property Trust is subject to various legal proceedings, claims, and administrative proceedings arising in the ordinary course of business, some of which are expected to be covered by liability insurance. Management makes assumptions and estimates concerning the likelihood and amount of any reasonably possible loss relating to these matters using the latest information available. Columbia Property Trust records a liability for litigation if an unfavorable outcome is probable and the amount of loss or range of loss can be reasonably estimated. If an unfavorable outcome is probable and a reasonable estimate of the loss is a range, Columbia Property Trust accrues the best estimate within the range. If no amount within the range is a better estimate than any other amount, Columbia Property Trust accrues the minimum amount within the range. If an unfavorable outcome is probable but the amount of the loss cannot be reasonably estimated, Columbia Property Trust discloses the nature of the litigation and indicates that an estimate of the loss or range of loss cannot be made. If an unfavorable outcome is reasonably possible and the estimated loss is material, Columbia Property Trust discloses the nature and estimate of the possible loss of the litigation. Columbia Property Trust does not disclose information with respect to litigation where the possibility of an unfavorable outcome is considered to be remote. Based on current expectations, such matters, both individually and in the aggregate, are not expected to have a material adverse effect on the liquidity, results of operations, business, or financial condition of Columbia Property Trust. Columbia Property Trust is not currently involved in any legal proceedings of which management would consider the outcome to be reasonably likely to have a material adverse effect on the results of operations or financial condition of Columbia Property Trust.

Stockholders' Equity and Partne

Stockholders' Equity and Partner's Capital	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stockholders' Equity and Partner's Capital	Stockholders' Equity and Partner's Capital Common Stock Repurchase Program Columbia Property Trust's board of directors authorized the repurchase of up to an aggregate of $200.0 million of its common stock, par value $0.01 per share, from September 4, 2019 through September 4, 2021 (the "2019 Stock Repurchase Program"). Under the 2019 Stock Repurchase Program, Columbia Property Trust acquired 1.6 million shares at an average price of $20.72 per share, for aggregate purchases of $33.5 million during 2019. As of December 31, 2019, $166.5 million remains available for repurchases under the 2019 Stock Repurchase Program. Common stock repurchases are charged against equity as incurred, and the repurchased shares are retired. Columbia Property Trust will continue to evaluate the purchase of shares, primarily through open market transactions, which are subject to market conditions and other factors. Long-Term Incentive Plan Employee Awards Columbia Property Trust maintains a stockholder-approved, long-term incentive plan that provides for grants of stock to be made to certain employees and independent directors of Columbia Property Trust (as amended and restated, the "LTI Plan"). In May 2017, Columbia Property Trust's stockholders approved the LTI Plan, and 4.8 million shares are authorized and reserved for issuance under the LTI Plan. Columbia Property Trust's LTI Plan includes both time-based awards and performance-based awards for all participants. Time-based awards vest ratably on each anniversary of the grant date over the next four three one one three one two The 2020 LTI Plan awards are consistent with the LTI Plan awards granted in the three prior years. On January 1, 2020, Columbia Property Trust granted 165,233 shares of time-based stock awards to employees, which will vest ratably on each anniversary of the grant over the next four three one Below is a summary of the employee awards issued under the LTI Plan for 2019, 2018, and 2017: Restricted Shares RSUs Shares Estimated Fair Value (1) Units Estimated Fair Value (2) Unvested as of January 1, 2017 256 $ 22.62 — $ — Granted 333 $ 21.59 331 $ 18.78 Vested (193) $ 22.42 — $ — Forfeited (7) $ 21.81 (2) $ 19.01 Unvested as of December 31, 2017 389 $ 21.85 329 $ — Granted 139 $ 22.97 206 $ 20.55 Vested (153) $ 22.13 (70) $ 19.47 Forfeited — $ — (11) $ 18.60 Unvested as of December 31, 2018 375 $ 22.15 454 $ 19.37 Granted 176 $ 19.36 257 $ 17.66 Vested (165) $ 21.99 (121) $ 19.08 Forfeited (12) $ 20.66 (6) $ 18.67 Unvested as of December 31, 2019 374 (3) $ 20.96 584 (3) $ 18.86 (1) Reflects the weighted-average grant-date fair value using the market closing price on the date of the grant. (2) Reflects the weighted-average grant-date fair value using a Monte Carlo valuation. (3) As of December 31, 2019, Columbia Property Trust expects approximately 360,000 of the 374,000 unvested restricted shares to ultimately vest and approximately 562,000 of the 584,000 unvested RSUs to ultimately vest, assuming a forfeiture rate of 4%, which was determined based on peer company data, adjusted for the specifics of the LTI Plan. Director Stock Grants Columbia Property Trust grants equity retainers to its directors under the LTI Plan. Such grants vest immediately. Beginning in May 2017, these grants are made annually for the following year and vest immediately. Prior to this time, the independent directors' equity retainers were paid quarterly. During 2019, 2018, and 2017, Columbia Property Trust granted the following equity retainers: Date of Grant Shares Grant-Date Fair Value (1) 2019 Director Grants: May 14, 2019 28,000 $ 22.13 2018 Director Grants: May 14, 2018 31,743 $ 22.20 2017 Director Grants: January 3, 2017 8,279 $ 21.58 May 2, 2017 33,581 $ 22.57 November 27, 2017 (2) 1,596 $ 23.07 (1) Columbia Property Trust determined the grant-date fair value using the market closing price on the date of the grant. (2) In November 2017, a new director was appointed to the board of directors of Columbia Property Trust. The new director received a pro-rated annual equity retainer grant at appointment. Stock-Based Compensation Expense Columbia Property Trust incurred stock-based compensation expense related to the following events (in thousands): 2019 2018 2017 Amortization of unvested LTI Plan awards $ 3,282 $ 3,800 $ 4,098 Future employee awards (1) 2,720 2,461 2,509 Issuance of shares to independent directors 620 705 973 Total stock-based compensation expense $ 6,622 $ 6,966 $ 7,580 (1) Reflects amortization of LTI Plan awards for service during the current period, for which shares will be issued in future periods. These expenses are included in general and administrative expenses – corporate in the accompanying consolidated statements of operations. There were $9.5 million and $8.6 million of unrecognized compensation costs related to unvested awards under the LTI Plan as of December 31, 2019 and December 31, 2018, respectively. This amount will be amortized over the respective vesting period, ranging from one year to four years at the time of grant. Independent Director Stock Option Plan Columbia Property Trust previously maintained an independent director stock option plan that provided for grants of stock to be made to independent directors of Columbia Property Trust (the "Director Plan"). A total of 25,000 shares were authorized and reserved for issuance under the Director Plan, which was suspended in April of 2008. Under the Director Plan, options were granted upon appointment to the board and on each annual meeting date. As of January 1, 2017, Columbia Property Trust had 1,375 options outstanding under this plan, all of which expired in 2017. There are no remaining options outstanding under the Director Plan. Columbia OP Partner's Capital Columbia Property Trust is the general partner and was the sole owner of Columbia OP for all periods presented.

Supplemental Disclosures of Non

Supplemental Disclosures of Noncash Investing and Financing Activities	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Supplemental Disclosures of Noncash Investing and Financing Activities	Supplemental Disclosures of Noncash Investing and Financing Activities Outlined below are significant noncash investing and financing activities for Columbia Property Trust, Inc. for the years ended December 31, 2019, 2018, and 2017 (in thousands): Years Ended December 31, 2019 2018 2017 Investment in real estate funded with other assets $ — $ 617 $ 311 Deposits applied to sales of real estate $ — $ — $ 10,000 Other assets assumed upon acquisition $ 6 $ 259 $ 1,014 Other liabilities assumed upon acquisition $ 137 $ 664 $ 268 Real estate assets transferred to unconsolidated joint venture $ — $ — $ 558,122 Other assets transferred to unconsolidated joint venture $ — $ — $ 43,700 Other liabilities transferred to unconsolidated joint venture $ — $ — $ 21,347 Extinguishment of 263 Shuman Boulevard mortgage note by transferring property to lender $ — $ 49,000 $ — Settlement of capital lease obligation with related development authority bonds $ — $ 120,000 $ — Amortization of net discounts on debt $ 180 $ 180 $ 180 Accrued investments in unconsolidated joint ventures $ 198 $ 386 $ — Accrued capital expenditures and deferred lease costs $ 12,944 $ 15,145 $ 25,069 Operating lease liability recorded at adoption of ASC 842 $ 34,791 $ — $ — Accrued dividends payable $ 24,209 $ 23,340 $ 23,961 Cumulative-effect adjustment to equity for the adoption of ASU 2017-05 and 2014-09 $ — $ 358,098 $ — Market value adjustment to interest rate swaps that qualify for hedge accounting treatment $ (3,445) $ 1,441 $ 1,786 Common stock issued to employees and directors, and amortized (net of income tax witholdings) $ 6,622 $ 6,966 $ 7,580

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leases Columbia Property Trust as Lessee Columbia Property Trust is a lessee with respect to ground leases at certain of its investment properties, office space leases, and various information technology equipment leases. Operating lease assets represent Columbia Property Trust's right to use the underlying asset over the lease term, and operating lease liabilities represent Columbia Property Trust's obligation to make lease payments over the lease term. Operating lease liabilities are measured as the present value of lease payments over the lease term. As most of Columbia Property Trust's leases do not provide an implicit rate, Columbia Property Trust uses its incremental borrowing rate, based on information available at commencement, to calculate the present value of lease payments. Lease term extensions are included in the operating lease liability when it is reasonably certain that they will be exercised. Any variable payments for non-lease services provided under leases are expensed as incurred. Operating lease assets are measured based on the corresponding operating lease liability amount, reduced for lease incentives. At adoption of ASC 842, straight-line rent payable (receivable) balances and intangible lease asset (liability) balances were reclassified to the corresponding right of use assets. Operating lease expense is recognized on a straight-line basis over the lease term, and is recorded as property operating costs for ground leases and as general and administrative – corporate for all other operating leases. Contracts are evaluated at commencement to determine if the contract contains a lease, and the appropriate classification for such leases. As of December 31, 2019, Columbia Property Trust has one ground lease with a remaining lease term of 58.0 years, inclusive of renewal options, which is included in operating lease assets of $29.5 million. Payments for all future periods under this ground lease have already been made. Thus, as of December 31, 2019, operating lease liabilities of $2.2 million include only the present value of future payments due under an office lease, which has a remaining lease term of 3.0 years. As of December 31, 2019, the future minimum lease payments to be made by Columbia Property Trust under its operating lease are as follows (in thousands): 2020 $ 728 2021 760 2022 793 2023 67 2024 — Thereafter — Total lease payments 2,348 Less: interest expense (162) Present value of lease liabilities $ 2,186 Weighted-average remaining lease term (years) 3.1 years Weighted-average discount rate 4.5 % Columbia Property Trust's operating leases had the following impacts on the consolidated balance sheet as of December 31, 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Assets: Total operating lease assets $ 27,843 $ 1,627 $ 29,470 Liabilities: Total operating lease liabilities $ — $ 2,186 $ 2,186 Columbia Property Trust's operating leases had the following impacts on the consolidated statements of operations for 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Property operating costs $ 2,165 $ — $ 2,165 General and administrative – corporate — 580 580 Total operating lease expenses $ 2,165 $ 580 $ 2,745 Columbia Property Trust's operating leases had the following impacts on the consolidated statements of cash flows for the 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Cash paid for operating lease liabilities included in cash flows from operations $ (1,329) $ (697) $ (2,026) Columbia Property Trust as Lessor Columbia Property Trust owns and leases commercial real estate, primarily office space, to tenants under operating leases for specified periods of time. Some of Columbia Property Trust's leases contain extension and/or termination options; however, the exercise of these extensions or terminations is at the discretion of the tenant and subject to negotiations. Therefore, such options are only recognized once they are deemed reasonably certain, typically at the time the option is exercised. Rental income related to such leases is recognized on a straight-line basis over the remaining lease period, and is included in lease revenues on the consolidated statements of operations. If at any point during the term of a lease, it is determined that the collectability of a tenant receivable is not probable, such receivable is written off against lease revenues. Contracts are evaluated at commencement to determine if the contract contains a lease, as defined by ASC 842, and the appropriate classification for such leases. In making this determination, Columbia Property Trust evaluates, among other things, whether the customer has the right to control the use of the identified asset. As of December 31, 2019, the weighted-average remaining term for such leases is approximately 7.4 years. Lease revenues include fixed and variable payments. Fixed payments primarily relate to base rent and include payments related to lease termination fees; and variable payments primarily relate to tenant reimbursements for certain property operating costs. Lease termination fees are recognized on a straight-line basis from the point at which Columbia Property Trust receives notification of termination until the date the tenant loses the right to lease the space and Columbia Property Trust has satisfied all obligations under the lease or termination agreement. During 2019, 2018, and 2017, Columbia Property Trust earned lease termination fees of $0.4 million, $2.2 million, and $0.4 million, respectively. Fixed and variable payments for 2019 are as follows (in thousands): Fixed payments $ 250,077 Variable payments 26,072 Total lease revenues $ 276,149 As of December 31, 2019, the future minimum fixed lease payments due to Columbia Property Trust under non-cancelable operating leases are as follows (thousands): 2020 $ 223,249 2021 224,999 2022 216,210 2023 205,955 2024 197,846 Thereafter 1,028,119 Total $ 2,096,378
Leases	Leases Columbia Property Trust as Lessee Columbia Property Trust is a lessee with respect to ground leases at certain of its investment properties, office space leases, and various information technology equipment leases. Operating lease assets represent Columbia Property Trust's right to use the underlying asset over the lease term, and operating lease liabilities represent Columbia Property Trust's obligation to make lease payments over the lease term. Operating lease liabilities are measured as the present value of lease payments over the lease term. As most of Columbia Property Trust's leases do not provide an implicit rate, Columbia Property Trust uses its incremental borrowing rate, based on information available at commencement, to calculate the present value of lease payments. Lease term extensions are included in the operating lease liability when it is reasonably certain that they will be exercised. Any variable payments for non-lease services provided under leases are expensed as incurred. Operating lease assets are measured based on the corresponding operating lease liability amount, reduced for lease incentives. At adoption of ASC 842, straight-line rent payable (receivable) balances and intangible lease asset (liability) balances were reclassified to the corresponding right of use assets. Operating lease expense is recognized on a straight-line basis over the lease term, and is recorded as property operating costs for ground leases and as general and administrative – corporate for all other operating leases. Contracts are evaluated at commencement to determine if the contract contains a lease, and the appropriate classification for such leases. As of December 31, 2019, Columbia Property Trust has one ground lease with a remaining lease term of 58.0 years, inclusive of renewal options, which is included in operating lease assets of $29.5 million. Payments for all future periods under this ground lease have already been made. Thus, as of December 31, 2019, operating lease liabilities of $2.2 million include only the present value of future payments due under an office lease, which has a remaining lease term of 3.0 years. As of December 31, 2019, the future minimum lease payments to be made by Columbia Property Trust under its operating lease are as follows (in thousands): 2020 $ 728 2021 760 2022 793 2023 67 2024 — Thereafter — Total lease payments 2,348 Less: interest expense (162) Present value of lease liabilities $ 2,186 Weighted-average remaining lease term (years) 3.1 years Weighted-average discount rate 4.5 % Columbia Property Trust's operating leases had the following impacts on the consolidated balance sheet as of December 31, 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Assets: Total operating lease assets $ 27,843 $ 1,627 $ 29,470 Liabilities: Total operating lease liabilities $ — $ 2,186 $ 2,186 Columbia Property Trust's operating leases had the following impacts on the consolidated statements of operations for 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Property operating costs $ 2,165 $ — $ 2,165 General and administrative – corporate — 580 580 Total operating lease expenses $ 2,165 $ 580 $ 2,745 Columbia Property Trust's operating leases had the following impacts on the consolidated statements of cash flows for the 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Cash paid for operating lease liabilities included in cash flows from operations $ (1,329) $ (697) $ (2,026) Columbia Property Trust as Lessor Columbia Property Trust owns and leases commercial real estate, primarily office space, to tenants under operating leases for specified periods of time. Some of Columbia Property Trust's leases contain extension and/or termination options; however, the exercise of these extensions or terminations is at the discretion of the tenant and subject to negotiations. Therefore, such options are only recognized once they are deemed reasonably certain, typically at the time the option is exercised. Rental income related to such leases is recognized on a straight-line basis over the remaining lease period, and is included in lease revenues on the consolidated statements of operations. If at any point during the term of a lease, it is determined that the collectability of a tenant receivable is not probable, such receivable is written off against lease revenues. Contracts are evaluated at commencement to determine if the contract contains a lease, as defined by ASC 842, and the appropriate classification for such leases. In making this determination, Columbia Property Trust evaluates, among other things, whether the customer has the right to control the use of the identified asset. As of December 31, 2019, the weighted-average remaining term for such leases is approximately 7.4 years. Lease revenues include fixed and variable payments. Fixed payments primarily relate to base rent and include payments related to lease termination fees; and variable payments primarily relate to tenant reimbursements for certain property operating costs. Lease termination fees are recognized on a straight-line basis from the point at which Columbia Property Trust receives notification of termination until the date the tenant loses the right to lease the space and Columbia Property Trust has satisfied all obligations under the lease or termination agreement. During 2019, 2018, and 2017, Columbia Property Trust earned lease termination fees of $0.4 million, $2.2 million, and $0.4 million, respectively. Fixed and variable payments for 2019 are as follows (in thousands): Fixed payments $ 250,077 Variable payments 26,072 Total lease revenues $ 276,149 As of December 31, 2019, the future minimum fixed lease payments due to Columbia Property Trust under non-cancelable operating leases are as follows (thousands): 2020 $ 223,249 2021 224,999 2022 216,210 2023 205,955 2024 197,846 Thereafter 1,028,119 Total $ 2,096,378

Non-Lease Revenues

Non-Lease Revenues	12 Months Ended
	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Non-Lease Revenues	Non-Lease Revenues Columbia Property Trust applies Accounting Standard Codification 606, Revenues from Contracts with Customers ("ASC 606"), to its non-lease revenue streams outlined below. ASC 606 requires companies to perform a five-step analysis of transactions to determine when and how revenue is recognized. See Note 10, Leases , for information about revenues earned under leases. Asset and Property Management Fee Income Under asset and property management agreements in place with certain of its unconsolidated joint ventures, Columbia Property Trust earns revenue for performing asset and property management functions for properties owned through its joint ventures, as further described in Note 4, Unconsolidated Joint Ventures . During 2019, 2018, and 2017, Columbia Property Trust earned revenues of $7.5 million, $7.4 million, and $3.8 million, respectively, under these agreements. Asset and property management services are ongoing and routine, and are provided on a recurring basis. Therefore such fees are recognized ratably over the service period, usually a period of three months. Columbia Property Trust receives payments quarterly for asset management fees and monthly for property management fees. Leasing Override Fees Under the asset management agreements for certain properties owned through unconsolidated joint ventures, Columbia Property Trust is eligible to earn leasing override fees equal to a percentage of the total rental payments to be made by the tenant over the term of the lease. Such fees are required to be recognized when Columbia Property Trust's obligation to perform is complete, typically upon execution of the lease. Prior to January 1, 2018, such fees were not recognized until billable to the applicable joint venture, typically upon commencement of the lease. Upon implementing ASC 606, effective January 1, 2018, Columbia Property Trust accelerated the recognition of lease override fees related to a lease that had been executed but not yet commenced, by recording $0.3 million of lease override fees receivable as prepaid expenses and other assets and a cumulative-effect adjustment to increase equity by the same amount. During 2019 and 2018, Columbia Property Trust earned leasing override fees of $0.1 million and $0.2 million, respectively, which are included in asset and property management fee income on the accompanying consolidated statements of operations. During 2017, Columbia Property Trust did not earn any leasing override fees. Salary and Other Reimbursement Revenue Under the property management agreements for certain properties owned through unconsolidated joint ventures, Columbia Property Trust receives reimbursements for salaries and property operating costs for ongoing and routine services that are provided by Columbia Property Trust employees on a recurring basis. Such revenues are recognized ratably over the service period, usually a period of one month, three months, or one year. During 2019, 2018, and 2017, Columbia Property Trust earned salary and other reimbursement revenue of $4.5 million, $4.4 million, and $2.3 million, respectively. These amounts are included in other property income on the accompanying consolidated statements of income. Miscellaneous Revenue Columbia Property Trust also receives revenues for services provided to its tenants through the TRS Entities, including fitness centers, shuttles, and cafeterias, which are included in other property income on the accompanying consolidated statements of income. Such services are ongoing and routine, and are provided on a recurring basis. These revenues are recognized ratably over the service period, usually a period of one month or one quarter. During 2019, 2018, and 2017, Columbia Property Trust earned miscellaneous revenue of $0.3 million, $0.7 million, and $0.6 million, respectively. These amounts are included in other property income on the accompanying consolidated statements of income.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Columbia Property Trust's income tax basis net income during 2019, 2018, and 2017 (in thousands) follows: 2019 2018 2017 GAAP basis financial statement net income attributable to common stockholders $ 9,197 $ 9,491 $ 176,041 Increase (Decrease) in Net Income Resulting From: Depreciation and amortization expense for financial reporting purposes in excess of amounts for income tax purposes 41,648 43,753 33,918 Rental income accrued for financial reporting purposes in excess of (less than) amounts for income tax purposes (10,373) 7,145 (38,426) Net amortization of above-/below-market lease intangibles for financial reporting purposes less than amounts for income tax purposes (5,107) (5,990) (6,091) Interest expense for financial reporting purposes in excess of amounts for income tax purposes 5,852 — — Bad debt expense for financial reporting purposes less than (in excess of) amounts for income tax purposes 1 4 (31) Income from unconsolidated joint ventures for financial reporting purposes in excess of amount for income tax purposes 15,224 16,654 13,902 Gains or losses on disposition of real property for financial reporting purposes that are more favorable than amounts for income tax purposes (57,284) 79,376 (126,770) Other expenses or revenues for financial reporting purposes in excess (less than) of amounts for income tax purposes 37,912 (32,342) 11,331 Income tax basis net income, prior to dividends-paid deduction $ 37,070 $ 118,091 $ 63,874 As of December 31, 2019, the tax basis carrying value of Columbia Property Trust's total assets was approximately $4.4 billion. For income tax purposes, distributions to common stockholders are characterized as ordinary income, capital gains, or as a return of a stockholder's invested capital. Columbia Property Trust's distributions per common share are summarized as follows: 2019 2018 2017 Ordinary income 53.1 % 100.0 % 58.5 % Capital gains — % — % — % Return of capital 46.9 % — % 41.5 % Total 100.0 % 100.0 % 100.0 % As of December 31, 2019, returns for the calendar years 2015 through 2019 remain subject to examination by U.S. or various state tax jurisdictions. No provisions for federal income taxes have been made in the accompanying consolidated financial statements, other than the provisions relating to the TRS Entities, as Columbia Property Trust made distributions in excess of taxable income for the periods presented. Columbia Property Trust is subject to certain state and local taxes related to property operations in certain locations, which have been provided for in the accompanying consolidated financial statements. The income taxes recorded by the TRS Entities for the years ended December 31, 2019, 2018, and 2017, are as follows: Years Ended December 31, 2019 2018 2017 Federal income tax $ 14 $ 63 $ 188 State income tax 6 (26) 38 Total income tax $ 20 $ 37 $ 226

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The basic and diluted earnings-per-share computations and net income have been reduced for the dividends paid on unvested shares related to the LTI Plan grants, as described in Note 8, Stockholders' Equity and Partner's Capital . The following table reconciles the numerator for the basic and diluted earnings-per-share computations shown on the consolidated statements of income (in thousands): 2019 2018 2017 Net income attributable to common stockholders $ 9,197 $ 9,491 $ 176,041 Distributions paid on unvested shares (310) (296) (337) Net income attributable to common stockholders used to calculate basic and diluted earnings per share $ 8,887 $ 9,195 $ 175,704 The following table reconciles the denominator for the basic and diluted earnings-per-share computations shown on the consolidated statements of income (in thousands): 2019 2018 2017 Weighted-average common shares – basic 116,261 117,888 120,795 Plus Incremental Weighted-Average Shares from Time-Vested Conversions Less Assumed Share Repurchases: Previously granted LTI Plan awards, unvested 114 104 116 Future LTI Plan awards 83 319 248 Weighted-average common shares – diluted 116,458 118,311 121,159

Quarterly Results (Unaudited)

Quarterly Results (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results (Unaudited)	Quarterly Results (Unaudited) Presented below is a summary of the unaudited quarterly financial information for the years ended December 31, 2019 and 2018 (in thousands, except per-share data): 2019 First Second Quarter Third Quarter Fourth Quarter Revenues $ 75,433 $ 72,730 $ 71,949 $ 68,725 Net income (loss) attributable to common stockholders $ 3,513 $ 47,747 (1) $ (20,286) (2) $ (21,777) (3) Net income (loss) attributable to common stockholders per share – basic (4) $ 0.03 $ 0.41 $ (0.17) $ (0.19) Net income (loss) attributable to common stockholders per share – diluted (4) $ 0.03 $ 0.41 $ (0.17) $ (0.19) Dividends declared per share $ 0.20 $ 0.20 $ 0.20 $ 0.21 2018 First Second Quarter Third Quarter Fourth Quarter Revenues $ 73,710 $ 75,370 $ 73,340 $ 75,523 Net income (loss) attributable to common stockholders $ 1,498 $ (3,439) (5) $ 6,429 $ 5,003 Net income (loss) attributable to common stockholders – basic (4) $ 0.01 $ (0.03) $ 0.05 $ 0.04 Net income (loss) attributable to common stockholders – diluted (4) $ 0.01 $ (0.03) $ 0.05 $ 0.04 Dividends declared per share $ 0.20 $ 0.20 $ 0.20 $ 0.20 (1) Net income attributable to common stockholders for the second quarter of 2019 includes a gain on sale of real estate assets of $41.9 million, as described in Note 3, Real Estate Transactions. (2) Net loss attributable to common stockholders for the third quarter of 2019 includes an impairment loss on real estate of $23.4 million related to sales of real estate assets, as described in Note 3, Real Estate Transactions. (3) Net loss attributable to common stockholders for the third quarter of 2019 includes an impairment loss on real estate of $20.6 million related to sales of real estate assets, as described in Note 2, Summary of Significant Accounting Policies. (4) Quarterly net income (loss) per share – basic and diluted is calculated based on quarterly basic and diluted weighted-average shares outstanding, respectively. (5) Net loss attributable to common stockholders for the second quarter of 2018 includes an impairment loss on real estate of $30.8 million related to sales of real estate assets, as described in Note 3, Real Estate Transactions , and a gain on extinguishment of debt of $24.0 million, related to the settlement of a mortgage note, as described in Note 5 , Line of Credit and Notes Payable.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information Columbia Property Trust establishes operating segments at the property level, and aggregates individual properties into reportable segments for high-barrier-to-entry markets and other geographic locations in which Columbia Property Trust has significant investments. Columbia Property Trust considers geographic location when evaluating its portfolio composition, and in assessing the ongoing operations and performance of its properties. As of December 31, 2019, Columbia Property Trust had the following reportable segments: New York, San Francisco, Washington, D.C., Boston, Los Angeles, and all other office markets. The all other office markets reportable segment consists of properties in similar low-barrier-to-entry geographic locations in which Columbia Property Trust does not have a substantial presence and/or does not plan to make further investments. Upon selling its remaining properties in Atlanta, Columbia Property Trust has combined Atlanta and the all other office markets reportable segment for all periods presented. During the periods presented, there have been no material intersegment transactions. Net operating income ("NOI") is a non-GAAP financial measure and is not considered a measure of operating results or cash flows from operations under GAAP. NOI is the primary performance measure reviewed by management to assess operating performance of properties and is calculated by deducting operating expenses from operating revenues. Operating revenues include lease revenues, hotel income, and other property income; and operating expenses include property and hotel operating costs. The NOI performance metric consists of only revenues and expenses directly related to real estate rental operations. NOI reflects property acquisitions and dispositions, occupancy levels, rental rate increases or decreases, and the recoverability of operating expenses. NOI, as Columbia Property Trust calculates it, may not be directly comparable to similarly titled, but differently calculated, measures for other REITs. Asset information and capital expenditures by segment are not reported because Columbia Property Trust does not use these measures to assess performance. Depreciation and amortization expense, along with other expense and income items, are not allocated among segments. The following table presents property operating revenues by geographic reportable segment (in thousands): For the Years Ended December 31, 2019 2018 2017 New York (1) $ 157,244 $ 158,077 $ 123,280 San Francisco (2) 114,295 105,947 105,550 Washington, D.C. (3) 58,200 57,274 36,934 Boston 14,285 13,441 11,559 Los Angeles 7,754 7,783 7,462 All other office markets 41,321 57,395 59,263 Total office segments 393,099 399,917 344,048 Hotel — — 1,328 Corporate 3,137 3,165 579 Total $ 396,236 $ 403,082 $ 345,955 (1) Includes operating revenues for 101 Franklin Street from December 2, 2019 through December 31, 2019; and for one unconsolidated property, 114 Fifth Avenue, based on Columbia Property Trust's ownership interest (49.5%) from July 6, 2017 (acquisition date) through December 31, 2019. (2) Includes operating revenues for two unconsolidated properties, 333 Market Street and University Circle, based on Columbia Property Trust's ownership interests: 100.0% from January 1, 2017 through July 5, 2017; 77.5% from July 6, 2017 through January 31, 2018; and 55.0% from February 1, 2018 through December 31, 2019. (3) Includes operating revenues for two unconsolidated properties, Market Square and 1800 M Street, based on Columbia Property Trust's ownership interests: 51.0% for the Market Square for all periods presented; 55.0% for 1800 M Street from October 11, 2017 (acquisition date) through December 31, 2019. A reconciliation of GAAP revenues to operating revenues is presented below (in thousands): For the Years Ended December 31, 2019 2018 2017 Total revenues $ 288,837 $ 297,943 $ 289,000 Operating revenues included in income (loss) from unconsolidated joint ventures (1) 114,943 112,523 60,737 Less: asset and property management fee income (2) (7,544) (7,384) (3,782) Total property operating revenues $ 396,236 $ 403,082 $ 345,955 (1) Columbia Property Trust records its interest in properties held through unconsolidated joint ventures using the equity method of accounting, and reflects its interest in the operating revenues of these properties in income (loss) from unconsolidated joint ventures in the accompanying consolidated statements of operations. (2) See Note 11, Non-Lease Revenues , of the accompanying consolidated financial statements. The following table presents net operating income by geographic reportable segment (in thousands): For the Years Ended December 31, 2019 2018 2017 New York (1) $ 93,112 $ 94,765 $ 73,893 San Francisco (2) 83,305 79,354 76,163 Washington, D.C. (3) 33,953 34,750 18,496 Boston 7,539 7,205 5,380 Los Angeles 4,601 4,590 4,529 All other office markets 35,428 51,638 52,153 Total office segments 257,938 272,302 230,614 Hotel — — (913) Corporate (904) (803) (826) Total $ 257,034 $ 271,499 $ 228,875 (1) Includes NOI for the following unconsolidated properties based on Columbia Property Trust's ownership interest: • 114 Fifth Avenue: (49.5%) from July 6, 2017 (acquisition date) through December 31, 2019 • 799 Broadway: (49.7%) from October 3, 2018 (acquisition date) through December 31, 2019 (2) Includes NOI for the following unconsolidated properties based on Columbia Property Trust's ownership interests: • 333 Market Street and University Circle: (100.0%) from January 1, 2017 through July 5, 2017 • 333 Market Street and University Circle: (77.5%) from July 6, 2017 through January 31, 2018 • 333 Market Street and University Circle: (55.0%) from February 1, 2018 through December, 2019 (3) Includes NOI for the following unconsolidated properties based on Columbia Property Trust's ownership interest: • Market Square: (51.0%) for all periods presented • 1800 M Street: (55.0%) from October 11, 2017 (acquisition date) through December 31, 2019 A reconciliation of GAAP net income to NOI is presented below (in thousands): For the Years Ended December 31, 2019 2018 2017 Net income attributable to common stockholders $ 9,197 $ 9,491 $ 176,041 Depreciation 78,292 81,795 80,394 Amortization 27,908 32,554 32,403 Impairment loss on real estate assets 43,941 30,812 — General and administrative – corporate 32,779 32,979 34,966 General and administrative – joint venture 3,567 3,108 1,454 Pre-acquisition costs 6,398 — — Net interest expense 42,997 56,477 58,187 Interest income from development authority bonds — (6,871) (7,200) (Gain) loss on extinguishment of debt — (23,340) 325 Income tax expense 21 37 (213) Asset and property management fee income (7,544) (7,384) (3,782) Adjustments included in loss from unconsolidated joint venture 61,634 62,603 31,818 Gain on sale of unconsolidated joint venture interest — (762) — Gains on sales of real estate assets (42,030) — (175,518) Adjustment attributable to noncontrolling interests (126) — — Net operating income $ 257,034 $ 271,499 $ 228,875

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Columbia Property Trust has evaluated subsequent events in connection with the preparation of its consolidated financial statements and notes thereto included in this report on Form 10-K and noted the following items in addition to those disclosed elsewhere in this report: On January 24, 2020, Columbia Property Trust acquired Normandy Real Estate Management, LLC, a developer, operator, and investment manager of office and mixed-use assets in New York, Boston, and Washington, D.C. for approximately $100.0 million, exclusive of transaction and closing costs (the "Normandy Acquisition"). The purchase price for the Normandy Acquisition is comprised of two components: an approximately $13.5 million cash payment, and the issuance of 3,264,151 Series A Convertible, Perpetual Preferred Units of Columbia OP with a liquidation preference of $26.50 per unit (the "Preferred OP Units"). The Preferred OP Units are convertible into common units of Columbia OP, which are convertible into shares of Columbia Property Trust's common stock, subject to certain terms and conditions. After giving effect to the Preferred OP Units issued in the Normandy Acquisition, Columbia Property Trust owns approximately 97.2% of the limited partnership interests in Columbia OP. Columbia Property Trust also notes the following other subsequent events: • On February 7, 2020, the board of directors declared dividends for the first quarter of 2020 of $0.21 per share, payable on March 17, 2020, to stockholders of record on March 2, 2020. • On January 24, 2020, in connection with the Normandy Acquisition, Columbia Property Trust issued 128,399 of time-based award shares of Columbia Property Trust stock and 104,968 of performance-based award restricted stock units to Normandy employees that became employees of Columbia Property Trust. • On January 16, 2020, Columbia Property Trust closed on the sale of Cranberry Woods Drive for $180.0 million and anticipates recognizing a gain on sale of real estate assets in the first quarter of 2020. • On January 7, 2020, Columbia Property Trust paid an aggregate amount of $24.2 million in dividends for the fourth quarter of 2019 to stockholders of record on December 16, 2019.

Schedule III - Real Estate Asse

Schedule III - Real Estate Assets and Accumulated Depreciation and Amortization	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Real Estate Assets and Accumulated Depreciation and Amortization	Columbia Property Trust, Inc. Initial Costs Costs Capitalized Subsequent to Acquisition Gross Amount at Which Carried at Accumulated Depreciation and Amortization Date of Construc- tion Life on Which Depreciation and Amortization is Computed (b) Description Location Owner- ship % Encum-brances Land Buildings and Improvements Total Land Buildings and Improvements Total (a) Date Acquired 80 M Street (c) Washington, D.C. 100 % None $ 26,248 $ 76,269 $ 102,517 $ 6,732 $ 26,806 $ 82,443 $ 109,249 $ 29,214 2001 6/29/2004 0 to 40 years 95 Columbus Jersey City, NJ 100 % None 29,061 141,544 170,605 13,137 29,712 154,030 183,742 72,086 1989 10/31/2006 0 to 40 years Pasadena Corporate Park Pasadena, CA 100 % None 53,099 59,630 112,729 (20,992) 41,604 50,133 91,737 22,463 1965/2000/ 2002/2003 7/11/2007 0 to 40 years Cranberry Woods Drive (c) Cranberry Township, PA 100 % None 15,512 173,062 188,574 15,187 15,512 188,249 203,761 58,079 2009/2010 6/1/2010 0 to 40 years 221 Main Street San Francisco, CA 100 % None 60,509 174,629 235,138 19,871 60,509 194,500 255,009 41,491 1974 4/22/2014 0 to 40 years 650 California Street San Francisco, CA 100 % None 75,384 240,441 315,825 27,757 75,384 268,198 343,582 49,732 1964 9/9/2014 0 to 40 years 315 Park Avenue South New York, NY 100 % None 119,633 249,510 369,143 35,718 119,633 285,228 404,861 38,039 1910 1/7/2015 0 to 40 years 116 Huntington Avenue Boston, MA 100 % None (d) — 116,290 116,290 26,670 — 142,960 142,960 25,824 1991 1/8/2015 0 to 40 years 229 West 43rd Street New York, NY 100 % None 207,233 292,991 500,224 2,226 207,233 295,217 502,450 47,597 1912/1924/ 1932/1947 8/4/2015 0 to 40 years 249 West 17th Street New York, NY 100 % None 113,149 221,517 334,666 4,354 113,149 225,871 339,020 18,867 1902/1909 10/11/2017 0 to 40 years 218 West 18th Street New York, NY 100 % None 43,836 139,077 182,913 5,716 43,836 144,793 188,629 14,868 1912 10/11/2017 0 to 40 years 149 Madison Avenue (e) New York, NY 100 % None 59,112 28,989 88,101 22,408 59,112 51,397 110,509 — (e) 11/28/2017 0 to 40 years 101 Franklin Street (e) New York, NY 92.5 % None 57,145 149,500 206,645 2,373 57,145 151,873 209,018 — (e) 12/2/2019 0 to 40 years 201 California Street San Francisco, CA 100 % None 77,833 170,754 248,587 3,334 77,833 174,088 251,921 719 1948 12/9/2019 0 to 40 years TOTAL CONSOLIDATED REAL ESTATE ASSETS (f) $ 937,754 $ 2,234,203 $ 3,171,957 $ 164,491 $ 927,468 $ 2,408,980 $ 3,336,448 $ 418,979 UNCONSOLIDATED REAL ESTATE ASSETS (presented at 100% of the Joint Venture's Basis) (g) : Market Square Washington, D.C. 51.0 % $ 325,000 $ 152,629 $ 450,757 $ 603,386 $ (15,552) $ 152,629 $ 435,205 $ 587,834 $ 59,629 1990 10/28/2015 0 to 40 years University Circle East Palo Alto, CA 55.0 % None 27,493 278,288 305,781 (96,941) 27,756 181,084 208,840 13,591 2001/2002/ 2003 7/6/2017 0 to 40 years 333 Market Street San Francisco, CA 55.0 % None 114,483 292,840 407,323 (41,230) 114,483 251,610 366,093 20,680 1979 7/6/2017 0 to 40 years 114 Fifth Avenue New York, NY 49.5 % None (h) — 383,694 383,694 2,301 — 385,995 385,995 52,714 1910 7/6/2017 0 to 40 years 1800 M Street Washington, D.C. 55.0 % None 125,735 272,353 398,088 35,285 125,735 307,638 433,373 32,459 1975 10/11/2017 0 to 40 years 799 Broadway (e) New York, NY 49.7 % $ 113,200 145,991 4,865 150,856 47,001 145,991 51,866 197,857 — (e) 10/3/2018 0 to 40 years TOTAL UNCONSOLIDATED REAL ESTATE ASSETS $ 566,331 $ 1,682,797 $ 2,249,128 $ (69,136) $ 566,594 $ 1,613,398 $ 2,179,992 $ 179,073 (a) The aggregate cost of consolidated land and buildings and improvements for federal income tax purposes is approximately $3.475 billion. (b) Columbia Property Trust assets are depreciated or amortized using the straight-line method over the useful lives of the assets by class. Generally, tenant improvements are amortized over the shorter of economic life or lease term, lease intangibles are amortized over the respective lease term, building improvements are depreciated over 5-25 years, and buildings are depreciated over 40 years. (c) 80 M Street and Cranberry Woods Drive are owned directly by Columbia Property Trust, Inc.; therefore, they are not consolidated into Columbia OP. (d) 116 Huntington Avenue is owned subject to a long-term, pre-paid ground lease. (e) 101 Franklin Street, 149 Madison, and 799 Broadway are under development. (f) Consolidated real estate assets excludes $3.2 million of corporate assets. (g) The aggregate cost of 100% of the land and buildings and improvements, net of debt, held by unconsolidated joint ventures for federal income tax purposes is approximately $1.834 billion. (h) Property is owned subject to a long-term ground lease. Columbia Property Trust Operating Partnership, L.P. Schedule III – Real Estate Assets and Accumulated Depreciation and Amortization (in thousands) For the Years Ended December 31, 2019 2018 2017 Real Estate: Balance at beginning of year $ 3,345,301 $ 3,612,294 $ 4,243,531 Additions to/improvements of real estate 531,336 87,398 698,567 Sale/transfer of real estate (456,331) (313,683) (1,285,915) (1) Impairment of real estate (43,941) (30,812) — Write-offs of building and tenant improvements (270) (1,464) (3,087) Write-offs of intangible assets (2) (34,039) (6,131) (14,432) Write-offs of fully depreciated assets (5,608) (2,301) (26,370) Balance at end of year $ 3,336,448 $ 3,345,301 $ 3,612,294 Accumulated Depreciation and Amortization: Balance at beginning of year $ 487,485 $ 482,627 $ 729,025 Depreciation and amortization expense 90,926 98,858 97,732 Sale/transfer of real estate (149,708) (84,965) (302,157) (1) Write-offs of tenant improvements (228) (603) (1,406) Write-offs of intangible assets (2) (3,888) (6,131) (14,197) Write-offs of fully depreciated assets (5,608) (2,301) (26,370) Balance at end of year $ 418,979 $ 487,485 $ 482,627 (1) Includes the transfer of 100% of both University Circle and 333 Market Street to unconsolidated joint ventures, in which Columbia Property Trust currently owned a 55.0% interest as of December 31, 2019. (2) Consists of write-offs of intangible lease assets related to lease restructurings, amendments, and terminations.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP"), which require us to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. Columbia Property Trust's consolidated financial statements include the accounts of Columbia Property Trust, Columbia OP, and their consolidated subsidiaries. Columbia OP's consolidated financial statements include the accounts of Columbia OP, and its consolidated subsidiaries. We consolidate any variable interest entity ("VIE") in which we are deemed the primary beneficiary. With respect to entities that are not VIEs, our consolidated financial statements also include the accounts of any entity in which we own a controlling financial interest, and any limited partnership in which we own a controlling general partnership interest. In determining whether Columbia Property Trust or Columbia OP owns a controlling interest, the following factors are considered, among other things: the ownership of voting interests, protective rights, and participatory rights of the investors.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the accompanying consolidated financial statements and the accompanying notes. Actual results could differ from those estimates.
Fair Value Measurements	Fair Value Measurements Columbia Property Trust estimates the fair value of its assets and liabilities (where currently required under GAAP) consistent with the provisions of Accounting Standard Codification 820, Fair Value Measurements ("ASC 820"). Under this standard, fair value is defined as the price that would be received upon sale of an asset or paid upon transfer of a liability in an orderly transaction between market participants at the measurement date. While various techniques and assumptions can be used to estimate fair value depending on the nature of the asset or liability, the accounting standard for fair value measurements and disclosures provides the following fair value technique parameters and hierarchy, depending upon availability: Level 1 – Assets or liabilities for which the identical term is traded on an active exchange, such as publicly traded instruments or futures contracts. Level 2 – Assets and liabilities valued based on observable market data for similar instruments. Level 3 – Assets or liabilities for which significant valuation assumptions are not readily observable in the market. Such assets or liabilities are valued based on the best available data, some of which may be internally developed. Significant assumptions may include risk premiums that a market participant would consider.
Real Estate Assets	Real Estate Assets Real estate assets are stated at cost, less accumulated depreciation and amortization. Amounts capitalized to real estate assets consist of the cost of acquisition or construction, and any tenant improvements or major improvements that extend the useful life of the related asset. All repairs and maintenance costs are expensed as incurred.
Assets Held for Sale	Assets Held for Sale Columbia Property Trust classifies properties as held for sale according to Accounting Standard Codification 360, Accounting for the Impairment or Disposal of Long-Lived Assets ("ASC 360"). According to ASC 360, properties having separately identifiable operations and cash flows, are considered held for sale when the following criteria are met: • Management, having the authority to approve the action, commits to a plan to sell the property. • The property is available for immediate sale in its present condition, subject only to terms that are usual and customary for sales of such property. • An active program to locate a buyer and other actions required to complete the plan to sell the property have been initiated. • The property is being actively marketed for sale at a price that is reasonable in relation to its current fair value. • Actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. • The sale of the property is probable and transfer of the property is expected to qualify for recognition as a completed sale, within one year.
Evaluating the Recoverability of Real Estate Assets	Evaluating the Recoverability of Real Estate Assets Columbia Property Trust continually monitors events and changes in circumstances that could indicate that the net carrying amounts of its real estate and related intangible assets and liabilities, of both operating properties and properties under redevelopment, may not be recoverable. When indicators of potential impairment are present that suggest that the net carrying amounts of real estate assets and related intangible assets and liabilities may not be recoverable, Columbia Property Trust assesses the recoverability of these net assets by determining whether the respective carrying values will be recovered through the estimated undiscounted future cash flows expected from the use of the net assets and their eventual disposition. In the event that such expected undiscounted future cash flows do not exceed the carrying values, Columbia Property Trust adjusts the carrying values of the real estate assets and related intangible assets and liabilities to the estimated fair values, pursuant to the property, plant, and equipment accounting standard for the impairment or disposal of long-lived assets, and recognizes an impairment loss. At such time that a property is required to be classified as held for sale, its net carrying amount is adjusted to the lower of its depreciated book value or its estimated fair value, less costs to sell, and depreciation is no longer recognized. Estimated fair values are calculated based on the following hierarchy of information: (i) recently quoted market prices, (ii) market prices for comparable properties, or (iii) the present value of future cash flows, including estimated residual value. Projections of expected future operating cash flows require that Columbia Property Trust estimate future market rental income amounts subsequent to the expiration of current lease agreements, property operating expenses, the number of months it takes to re-lease the property, and the number of years the property is held for investment, among other factors. Due to the inherent subjectivity of the assumptions used to project future cash flows, estimated fair values may differ from the values that would be realized in market transactions. Certain of
Allocation of Purchase Price of Acquired Assets	Allocation of Purchase Price of Acquired Assets Upon the acquisition of real properties, Columbia Property Trust allocates the purchase price of properties and related transaction costs to tangible assets, consisting of land, building, site improvements, and identified intangible assets and liabilities, including the value of in-place leases, based in each case on Columbia Property Trust's estimate of their fair values in accordance with ASC 820 (see "Fair Value Measurements" section above for additional details). In conjunction with certain acquisitions, Columbia Property Trust has entered into master lease agreements, which obligate the seller to pay rent pertaining to certain nonrevenue-producing spaces to mitigate the negative effects of lower rental revenues. Columbia Property Trust records payments receivable under such master lease agreements as a reduction of the property basis rather than income. Columbia Property Trust received no proceeds for master leases during 2019, 2018, or 2017. The fair values of the tangible assets of an acquired property (which includes land, building, and site improvements) are determined by valuing the property as if it were vacant, and the "as-if-vacant" value is then allocated to land, building, and site improvements based on management's determination of the relative fair value of these assets. Management determines the as-if-vacant fair value of a property using methods similar to those used by independent appraisers. Factors considered by management in performing these analyses include an estimate of carrying costs during the expected lease-up periods considering current market conditions and costs to execute similar leases, including leasing commissions and other related costs. In estimating carrying costs, management includes real estate taxes, insurance, and other operating expenses during the expected lease-up periods based on current market demand.
Intangible Assets and Liabilities Arising From In-Place Leases Where Columbia Property Trust Is the Lessor	Intangible Assets and Liabilities Arising From In-Place Leases Where Columbia Property Trust Is the Lessor As further described below, in-place leases with Columbia Property Trust as the lessor may have values related to direct costs associated with obtaining a new tenant that are avoided for in-place leases, opportunity costs associated with lost rentals that are avoided by acquiring an in-place lease, tenant relationships, and effective contractual rental rates that are above or below market: • Direct costs associated with obtaining a new tenant that are avoided for in-place leases, including commissions, tenant improvement allowances, and other direct costs, are estimated based on management's consideration of current market costs to execute a similar lease. Such direct costs are included in intangible lease origination costs in the accompanying consolidated balance sheets and are amortized to expense over the remaining terms of the respective leases. • The value of opportunity costs associated with lost rentals avoided by acquiring an in-place lease is calculated based on contractual amounts to be paid pursuant to the in-place leases over a market absorption period for a similar lease. Such opportunity costs ("Absorption Period Costs") are included in intangible lease assets in the accompanying consolidated balance sheets and are amortized to expense over the remaining terms of the respective leases. • The value of effective rental rates of in-place leases that are above or below the market rates of comparable leases is calculated based on the present value (using a discount rate that reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be received pursuant to the in-place leases and (ii) management's estimate of fair market lease rates for the corresponding in-place leases. This calculation includes significantly below-market renewal options for which exercise of the renewal option appears to be reasonably assured. These intangible assets or liabilities are measured over the actual or assumed (in the case of renewal options) remaining lease terms. The capitalized above-market and below-market lease values are recorded as intangible lease assets or liabilities and amortized as an adjustment to rental income over the remaining terms of the respective leases.
Cash and Cash Equivalents	Cash and Cash EquivalentsColumbia Property Trust considers all highly liquid investments purchased with an original maturity of three
Tenant Receivables	Tenant ReceivablesTenant receivables consist of rental and reimbursement billings due from tenants. Tenant receivables are recorded at the original amount earned, which approximates fair value. Management assesses the realizability of tenant receivables on an ongoing basis, and, if at any point during the term of a lease it is determined that the collectability of a tenant receivable is not probable, such receivable is written off against lease revenues
Straight-Line Rent Receivable	Straight-Line Rent Receivable Straight-line rent receivable reflects the amount of cumulative adjustments necessary to present rental income on a straight-line basis. Columbia Property Trust recognizes rental revenues on a straight-line basis, ratably over the term of each lease; however, leases often provide for payment terms that differ from the revenue recognized. When the amount of cash billed is less than the amount of revenue recognized, typically early in the lease, straight-line rent receivable is recorded for the difference. The receivable is depleted during periods later in the lease when the amount of cash paid by the tenant is greater than the amount of revenue recognized.
Prepaid Expenses and Other Assets	Prepaid Expenses and Other Assets Prepaid expenses and other assets primarily include earnest money deposits, escrow accounts held by lenders to pay future real estate taxes, insurance and tenant improvements, notes receivable, nontenant receivables, prepaid taxes, insurance and operating costs, unamortized deferred financing costs related to the line of credit (the "Revolving Credit Facility"), interest rate swaps (when in an asset position), certain corporate assets, and deferred tax assets. Prepaid expenses are recognized over the period to which the good or service relates. Other assets are written off when the asset no longer has future value, or when the company is no longer obligated for the corresponding liability.
Deferred Lease Costs	Deferred Lease CostsDeferred lease costs include costs incurred to procure leases that are paid to third parties or tenants, and incentives that are provided to tenants under the terms of their leases. These costs are capitalized and amortized on a straight-line basis over the terms of the lease. Amortization of third-party leasing costs is reflected as amortization expense, and amortization of lease incentives is reflected as an adjustment to rental income.
Accounts Payable, Accrued Expenses, and Accrued Capital Expenditures	Accounts Payable, Accrued Expenses, and Accrued Capital ExpendituresAccounts payable, accrued expenses, and accrued capital expenditures primarily include payables related to property operations, capital projects, and interest rate swaps (when in a liability position).
Deferred Financing Costs/Line of Credit and Notes Payable and Bonds Payable	Deferred Financing CostsDeferred financing costs include costs incurred to secure debt from third-party lenders. Deferred financing costs, except for costs related to the Revolving Credit Facility, are presented as a direct reduction to the carrying amount of the related debt for all periods presented. Deferred financing costs related to the Revolving Credit Facility are included in prepaid expenses and other assets. Line of Credit and Notes Payable When debt is assumed, Columbia Property Trust records the loan at fair value. The fair value adjustment is amortized to interest expense over the term of the loan using the effective interest method. As described in the "Deferred Financing Costs" section above, line of credit and notes payable is presented on the accompanying consolidated balance sheet net of deferred financing costs related to term loans and notes payable of $2.1 million and $2.7 million as of December 31, 2019 and December 31, 2018, respectively. Bonds Payable
Preferred Stock, Common Stock and Distributions	Preferred Stock Columbia Property Trust is authorized to issue up to 100.0 million shares of one or more classes or series of preferred stock with a par value of $0.01 per share. Columbia Property Trust's board of directors may determine the relative rights, preferences, and privileges of each class or series of preferred stock issued, which may be more beneficial than the rights, preferences, and privileges attributable to Columbia Property Trust's common stock. To date, Columbia Property Trust has not issued any shares of preferred stock. Common Stock The par value of Columbia Property Trust's issued and outstanding shares of common stock is classified as common stock, with the remainder allocated to additional paid-in capital. Distributions To maintain its status as a REIT, Columbia Property Trust is required by the Internal Revenue Code of 1986, as amended (the "Code"), to make distributions to stockholders each taxable year equal to at least 90% of its REIT taxable income, computed without regard to the dividends-paid deduction and by excluding net capital gains attributable to stockholders ("REIT taxable income"). To the extent that Columbia Property Trust satisfies the distribution requirement but distributes less than 100% of its REIT taxable income, Columbia Property Trust would be subject to federal and state corporate income tax on the undistributed income. Distributions to the stockholders are determined by the board of directors of Columbia Property Trust and are dependent upon a number of factors relating to Columbia Property Trust, including funds available for payment of distributions, financial condition, the timing of property acquisitions, capital expenditure requirements, and annual distribution requirements in order to maintain Columbia Property Trust's status as a REIT under the Code.
Noncontrolling interests	Noncontrolling InterestsNoncontrolling interests represent the equity interests of a consolidated joint venture that are not owned by Columbia Property Trust. Noncontrolling interests are adjusted for contributions, distributions, and earnings attributable to the noncontrolling interest holders of the consolidated joint venture. Earnings are allocated to joint venture partners using the hypothetical liquidation at book value method, based on the terms of the respective joint venture agreements, and are recorded as net income (loss) attributable to noncontrolling interests in the accompanying consolidated statements of operations.
Interest Rate Swap Agreements	Interest Rate Swap Agreements Columbia Property Trust enters into interest rate swap contracts to mitigate its interest rate risk on the related financial instruments. Columbia Property Trust does not enter into derivative or interest rate transactions for speculative purposes and currently does not have any derivatives that are not designated as hedges; however, certain of its derivatives may, at times, not qualify for hedge accounting treatment. Columbia Property Trust records the fair value of its interest rate swaps on its consolidated balance sheet either as prepaid expenses and other assets or as accounts payable, accrued expenses, and accrued capital expenditures. Changes in the fair value of interest rate swaps that are designated as cash flow hedges are recorded as other comprehensive income (loss). Changes in the fair value of interest rate swaps that do not qualify for hedge accounting treatment are recorded as gain or loss on interest rate swaps. Amounts received or paid under interest rate swap agreements are recorded as interest expense for contracts that qualify for hedge accounting treatment and as loss on interest rate swaps for contracts
Revenue Recognition	Revenue Recognition The majority of Columbia Property Trust’s revenues are derived from leases and are reflected as lease revenues on the accompanying consolidated statements of operations. For more information about Columbia Property Trust's lease revenue streams see Note 10, Leases . In determining when to begin recognizing rental revenues, Columbia Property Trust considers a number of factors, including the nature of the physical improvements made in connection with the lease. When Columbia Property Trust owns the improvements for accounting purposes, revenue recognition generally begins once the improvements are substantially complete and the lessee has taken possession of the improved space. When Columbia Property Trust does not own the improvements for accounting purposes (the lessee is the owner), revenue recognition generally begins once the lessee takes possession of the unimproved space; in these instances, the tenant allowance is accounted for as a lease incentive, which reduces rental revenues over the lease term. When evaluating which party (lessee or lessor) owns the improvements for accounting purposes, Columbia Property Trust considers a number of factors, including, among other things: whether the lease stipulates what the tenant allowance may be used for; whether the lessee or lessor retains legal title to the improvements; the expected economic life of the improvements relative to the lease term; and who directs the construction of the improvements. The determination of who owns the improvements for accounting purposes is subject to significant judgement and is not based on any one factor.
Income Taxes	Income Taxes Columbia Property Trust has elected to be taxed as a REIT under the Code, as amended (the "Code") and has operated as such beginning with its taxable year ended December 31, 2003. To qualify as a REIT, Columbia Property Trust must meet certain organizational and operational requirements, including a requirement to distribute at least 90% of its REIT taxable income, as defined by the Code, to its stockholders. To the extent that Columbia Property Trust satisfies the distribution requirement but distributes less than 100% of its REIT taxable income, Columbia Property Trust would be subject to federal and state corporate income tax on the undistributed income. Generally, Columbia Property Trust does not incur federal income taxes, other than as described in the following paragraph, because its stockholder distributions typically exceed its taxable income due to noncash expenses such as depreciation. Columbia Property Trust is, however, subject to certain state and local taxes related to the operations of properties in certain locations, which have been provided for in the accompanying consolidated financial statements. Columbia Property Trust TRS, LLC, Columbia KCP TRS, LLC, and Columbia Energy TRS, LLC (collectively, the "TRS Entities") are wholly owned subsidiaries of Columbia Property Trust and are organized as Delaware limited liability companies. The TRS Entities, among other things, provide tenant services that Columbia Property Trust, as a REIT, cannot otherwise provide. Columbia Property Trust has elected to treat the TRS Entities as taxable REIT subsidiaries. Columbia Property Trust may perform certain additional, noncustomary services for tenants of its buildings through the TRS Entities; however, any earnings related to such services are subject to federal and state income taxes. In addition, for Columbia Property Trust to continue to qualify as a REIT, Columbia Property Trust must limit its investments in taxable REIT subsidiaries to 20% of the value of the total assets. The TRS Entities' deferred tax assets and liabilities represent temporary differences between the financial reporting basis and the tax basis of assets and liabilities based on the enacted rates expected to be in effect when the temporary differences reverse. If applicable, Columbia Property Trust records interest and penalties related to uncertain tax positions as general and administrative expense in the accompanying consolidated statements of operations.
Segment Information	Segment Information As of December 31, 2019, Columbia Property Trust's reportable segments are determined based on the geographic markets in which it has significant investments. Columbia Property Trust considers geographic location when evaluating its portfolio composition, and in assessing the ongoing operations and performance of its properties (see Note 15, Segment Information ).
Reclassification	Reclassification In accordance with Accounting Standard Codification 360, Property, Plant, and Equipment ("ASC 360"), and in response to the Securities and Exchange Commission's Disclosure Update and Simplification
Recent Accounting Pronouncements	Recent Accounting Pronouncements Effective January 1, 2019, Columbia Property Trust adopted Accounting Standard Codification 842, Leases ("ASC 842"), which amends the lease accounting rules with the following key changes: • Lessees are required to record a right-of-use asset and a lease liability for all leases, as defined, with a term of greater than 12 months, and to classify such leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee, or not. This classification will determine whether the lease expense is recognized using the effective interest method (finance leases) or on a straight-line basis over the term of the lease (operating leases). • Lessors are required to account for leases using an approach that is substantially similar to the pre-existing rules for operating leases, sales-type leases, and direct financing leases, with a few targeted changes, including that: (i) lessors are no longer permitted to capitalize and amortize initial indirect costs incurred to obtain a lease, and (ii) provisions for uncollectible tenant receivables are reflected as a reduction to lease revenues, instead of as general and administrative expense. In connection with transitioning to ASC 842, Columbia Property Trust elected to use certain practical expedients which impact Columbia Property Trust as follows: • Prospective implementation. In-place contracts retain their character as to whether they meet the definition of a lease or not; in-place leases retain their classification as an operating, sales-type, or direct financing lease; and prior-period accounting and presentation is unchanged. • Rental income and tenant reimbursements for operating leases are combined in a single line on the statements of operations for all periods presented. • Leases with a term of 12 months or less are expensed as incurred, as provided for in a practical expedient elected by Columbia Property Trust. See Note 10, Leases , for additional information. Accounting Standard Update 2018-13 , Fair Value Measurement: Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"), which will be effective for Columbia Property Trust on January 1, 2020, expands the disclosure requirements related to a change in fair value technique hierarchy. ASU 2018-13 is not expected to have a material impact on Columbia Property Trust's consolidated financial statements or disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives for Real Estate Assets	The estimated useful lives of its assets by class are as follows: Buildings 40 years Building and site improvements 5-25 years Tenant improvements Shorter of economic life or lease term Intangible lease assets Lease term
Assets and liabilities held for sale	The major classes of assets and liabilities classified as held for sale are provided below (in thousands): December 31, 2019 Real Estate Assets Held for Sale: Real estate assets, at cost: Land $ 57,117 Buildings and improvements, less accumulated depreciation of $80,543 157,701 Construction in progress 138 Total real estate assets held for sale, net $ 214,956 Other Assets Held for Sale: Tenant receivables $ 156 Straight-line rent receivable 12,591 Prepaid expenses and other assets 334 Deferred lease costs, less accumulated amortization of $10,222 10,836 Total other assets held for sale, net $ 23,917 Liabilities Held for Sale: Accounts payable, accrued expenses, and accrued capital expenditures $ 1,151 Deferred income 1,903 Total liabilities held for sale $ 3,054
Schedule of Intangible Assets and Liabilities	As of December 31, 2019 and 2018, Columbia Property Trust had the following gross intangible in-place lease assets and liabilities (in thousands): Intangible Lease Assets Intangible Intangible Above-Market Absorption December 31, 2019 Gross $ 2,481 $ 117,203 $ 61,702 $ 36,966 Accumulated Amortization (1,202) (57,457) (33,731) (15,127) Net $ 1,279 $ 59,746 $ 27,971 $ 21,839 December 31, 2018 Gross $ 3,174 $ 147,668 $ 99,440 $ 42,847 Accumulated Amortization (1,060) (81,220) (65,348) (21,766) Net $ 2,114 $ 66,448 $ 34,092 $ 21,081 During 2019, 2018, and 2017, Columbia Property Trust recognized the following amortization of intangible lease assets and liabilities (in thousands): Intangible Lease Assets Intangible Intangible Above-Market Absorption For the Years Ended December 31, 2019 $ 288 $ 13,511 $ 7,398 $ 5,395 2018 $ 228 $ 17,137 $ 9,660 $ 6,851 2017 $ 519 $ 16,807 $ 10,124 $ 6,883
Schedule of Net Below-Market Lease Asset Amortization	The remaining net intangible assets and liabilities as of December 31, 2019, will be amortized as follows (in thousands): Intangible Lease Assets Intangible Intangible Above-Market Absorption For the Years Ending December 31, 2020 $ 172 $ 12,871 $ 5,866 $ 5,483 2021 172 9,328 4,516 3,191 2022 172 7,959 3,429 2,910 2023 172 6,455 2,903 2,336 2024 172 5,594 2,586 1,990 Thereafter 419 17,539 8,671 5,929 $ 1,279 $ 59,746 $ 27,971 $ 21,839 Weighted-average amortization period 6.6 years 5.0 years 4.9 years 5.3 years
Schedule of Interest Rate Derivatives	The following tables provide additional information related to Columbia Property Trust's interest rate swaps as of December 31, 2019 and 2018 (in thousands): Estimated Fair Value as of Instrument Type Balance Sheet Classification 2019 2018 Derivatives Designated as Hedging Instruments: Interest rate contracts Prepaid expenses and other assets $ 551 $ 2,344 Interest rate contracts Accounts payable $ 1,652 $ — Years Ended December 31, 2019 2018 2017 Market value adjustment to interest rate swaps designated as hedging instruments and included in other comprehensive income (loss) $ (3,445) $ 1,441 $ 1,786

Real Estate Transactions (Table

Real Estate Transactions (Tables)	12 Months Ended
	Dec. 31, 2019
Business Acquisitions and Dispositions [Abstract]
Interests in Properties Acquired	During 2019, 2018, and 2017, Columbia Property Trust acquired the following properties: Property Location Date Percent Acquired Purchase Price (in thousands) (1) 2019 201 California Street San Francisco, CA December 9, 2019 100.0 % $ 238,900 101 Franklin Street (2) New York, NY December 2, 2019 92.5 % $ 205,500 2018 Lindbergh Center – Retail Atlanta, GA October 24, 2018 100.0 % $ 23,000 799 Broadway New York, NY October 3, 2018 49.7 % $ 30,200 (3) 2017 149 Madison Avenue New York, NY November 28, 2017 100.0 % $ 87,700 1800 M Street Washington, D.C. October 11, 2017 55.0 % $ 231,550 (3) 249 West 17th Street & 218 West 18th Street New York, NY October 11, 2017 100.0 % $ 514,100 114 Fifth Avenue New York, NY July 6, 2017 49.5 % $ 108,900 (3) (1) Exclusive of transaction costs and price adjustments. See purchase price allocation table below for a breakout of the net purchase price for wholly owned properties. (2) Property is owned through a consolidated joint venture. (3) These properties are owned through unconsolidated joint ventures. Purchase price is for Columbia Property Trust's partial interests in the properties. Purchase Price Allocations for Consolidated Property Acquisitions 201 California Street 101 Franklin Street (1) 149 Madison Avenue 249 West 17th Street 218 West 18th Street Location San Francisco, CA New York, NY New York, NY New York, NY New York, NY Date Acquired December 9, 2019 December 2, 2019 November 28, 2017 October 11, 2017 October 11, 2017 Purchase Price: Land $ 77,833 $ 57,145 $ 59,112 $ 113,149 $ 43,836 Building and improvements 157,513 149,500 28,989 194,109 126,957 Intangible lease assets 13,241 — — 27,408 12,120 Intangible lease origination costs 5,785 — — 13,062 4,168 Intangible below market lease liability (8,064) — — (7,131) (11,757) Total purchase price $ 246,308 $ 206,645 $ 88,101 $ 340,597 $ 175,324 (1) Owned through a consolidated joint venture, in which Columbia Property Trust owns a 92.5% interest.
Business Acquisition, Pro Forma Information	The following unaudited pro forma statements of operations presented for 2019, 2018, and 2017, have been prepared for Columbia Property Trust to give effect to the acquisitions of 201 California Street and 101 Franklin Street as if the acquisitions had occurred on January 1, 2018; and 249 West 17th Street, 218 West 18th Street, and 149 Madison Avenue as if the acquisitions had occurred on January 1, 2016. The following unaudited pro forma financial results for Columbia Property Trust have been prepared for informational purposes only and are not necessarily indicative of future results or of actual results that would have been achieved had these acquisitions been consummated as of January 1, 2018 and January 1, 2016 (in thousands): 2019 2018 2017 Revenues $ 304,756 $ 312,003 $ 319,064 Net income attributable to common stockholders of Columbia Property Trust $ 17,600 $ 16,822 $ 183,318
Schedule of Properties Sold	During 2019, 2018, and 2017, Columbia Property Trust sold the following properties and partial interest in properties of unconsolidated joint ventures. Additional information for certain of the dispositions is provided below the table. Property Location Date % Sold Sale Price (1) (in thousands) Gain on Sale 2019 Lindbergh Center Atlanta, GA September 26, 2019 100.0 % $ 187,000 $ — One & Three Glenlake Parkway Atlanta, GA April 15, 2019 100.0 % $ 227,500 $ 42,030 2018 222 East 41st Street New York, NY May 29, 2018 100.0 % $ 332,500 $ — 263 Shuman Boulevard Chicago, IL April 13, 2018 100.0 % $ 49,000 $ 24,039 University Circle & San Francisco, CA February 1, 2018 22.5 % $ 235,300 (2) $ 762 2017 University Circle & 333 Market Street San Francisco, CA July 6, 2017 22.5 % $ 234,000 (2) $ 102,365 Key Center Tower & Marriott Cleveland, OH January 31, 2017 100.0 % $ 267,500 $ 9,466 Houston Properties Houston, TX January 6, 2017 100.0 % $ 272,000 $ 63,688 (1) Exclusive of transaction costs and price adjustments.

Unconsolidated Joint Ventures (

Unconsolidated Joint Ventures (Tables)	12 Months Ended
	Dec. 31, 2019
Equity Method Investments and Joint Ventures [Abstract]
Summary of Financial Information for the Joint Ventures	As of December 31, 2019 and December 31, 2018, Columbia OP owns interests in the following properties through joint ventures, which are accounted for using the equity method of accounting: Geographic Market Ownership Interest Carrying Value of Investment (1) Joint Venture Property Name December 31, 2019 December 31, 2018 Market Square Joint Venture Market Square Washington, D.C. 51.0 % $ 135,557 $ 134,250 University Circle Joint Venture University Circle San Francisco 55.0 % 283,633 292,951 333 Market Street Joint Venture 333 Market Street San Francisco 55.0 % 269,638 273,783 114 Fifth Avenue Joint Venture 114 Fifth Avenue New York 49.5 % 87,750 99,283 1800 M Street Joint Venture 1800 M Street Washington, D.C. 55.0 % 233,196 237,333 799 Broadway Joint Venture (2) 799 Broadway New York 49.7 % 44,686 (4) 33,753 $ 1,054,460 $ 1,071,353 (1) Includes basis differences. Columbia Property Trust's investments in unconsolidated joint ventures were greater than the historical costs recorded at the underlying joint venture level by $279.2 million and $282.0 million as of December 31, 2019 and December 31, 2018, respectively. Such basis differences result from the timing of each partner's joint venture interest acquisition; and formation costs incurred by Columbia Property Trust. Basis differences are amortized to income (loss) from unconsolidated joint ventures over the lives of the underlying assets or liabilities. (2) Columbia Property Trust capitalized interest of $1.3 million and $0.2 million on its investment in the 799 Broadway Joint Venture in 2019 and 2018, respectively. Summarized balance sheet information for each of the unconsolidated joint ventures is as follows (in thousands): Total Assets Total Debt Total Equity (1) December 31, 2019 December 31, 2018 December 31, 2019 December 31, 2018 December 31, 2019 December 31, 2018 Market Square Joint Venture $ 582,747 $ 582,176 $ 324,815 (2) $ 324,762 $ 241,719 $ 241,581 University Circle Joint Venture 216,546 224,746 — — 212,656 219,390 333 Market Street Joint Venture 367,652 375,884 — — 352,385 360,915 114 Fifth Avenue Joint Venture 485,442 377,970 — — 127,554 149,243 1800 M Street Joint Venture 437,439 447,585 — — 421,588 429,016 799 Broadway Joint Venture 201,210 168,390 109,735 (3) 95,630 85,316 67,189 $ 2,291,036 $ 2,176,751 $ 434,550 $ 420,392 $ 1,441,218 $ 1,467,334 (1) Excludes basis differences (see footnote (1) to the Carrying Value of Investment table above). (2) The Market Square Joint Venture has a mortgage note with an outstanding balance of $325.0 million as of December 31, 2019 and December 31, 2018. The Market Square mortgage note bears interest at 5.07% and matures on July 1, 2023. (3) Reflects $113.2 million outstanding, net of $3.5 million of net unamortized deferred financing costs, on the 799 Broadway construction loan. The 799 Broadway construction loan is being used to finance a portion of the 799 Broadway development project, has total capacity of $187.0 million, and bears interest at LIBOR, capped at 4.00%, plus a spread of 425 basis points (the "Construction Loan"). A portion of the monthly interest payments accrue into the balance of the loan. The Construction Loan matures on October 9, 2021, with two one Commitments and Contingencies . Summarized income statement information for the unconsolidated joint ventures for the years ended December 31, 2019, 2018, and 2017 is as follows (in thousands): Total Revenues Net Income (Loss) Columbia Property Trust's Share of Net Income (Loss) (1) 2019 2018 2017 2019 2018 2017 2019 2018 2017 Market Square Joint Venture $ 47,737 $ 44,815 $ 41,749 $ (11,515) $ (12,304) $ (15,192) $ (5,873) $ (6,275) $ (7,747) University Circle Joint Venture 44,427 43,581 19,386 24,251 23,776 9,826 13,338 13,478 7,561 333 Market Street Joint Venture 28,170 27,006 12,971 14,929 14,620 6,948 8,211 8,312 5,331 114 Fifth Avenue Joint Venture 42,921 41,169 20,133 (10,674) (10,256) (4,885) (5,283) (5,077) (2,820) 1800 M Street Joint Venture 38,377 37,486 8,005 4,887 4,239 619 2,688 2,332 326 799 Broadway Joint Venture — — — (882) (132) — (439) (66) — $ 201,632 $ 194,057 $ 102,244 $ 20,996 $ 19,943 $ (2,684) $ 12,642 $ 12,704 $ 2,651 (1) Excludes amortization of basis differences, as described in footnote (1) to the carrying value of investment table above, which are recorded as income (loss) from unconsolidated joint ventures in the accompanying consolidated statements of operations. 2019 2018 2017 Market Square Joint Venture $ 2,256 $ 2,156 $ 1,998 University Circle Joint Venture 2,313 2,283 1,000 333 Market Street Joint Venture 819 784 367 1800 M Street Joint Venture 2,156 2,161 417 $ 7,544 $ 7,384 $ 3,782

Line of Credit and Notes Paya_2

Line of Credit and Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Line of Credit and Notes Payable Indebtedness Outstanding (Excluding Bonds Payable)	As of December 31, 2019 and 2018, Columbia Property Trust had the following line of credit and notes payable indebtedness outstanding (excluding bonds payable; see Note 6, Bonds Payable ) in thousands: Rate as of Term Debt or Interest Only Outstanding Balance as of Facility Maturity 2019 2018 Revolving Credit Facility LIBOR + 90 bp (1) Interest only January 31, 2023 $ 334,000 $ 482,000 $300 Million Term Loan LIBOR + 100 bp (2) Interest only January 31, 2024 300,000 — $150 Million Term Loan LIBOR + 110 bp (3) Interest only July 29, 2022 150,000 150,000 Less: Deferred financing costs related to term loans (2,084) (2,692) Total indebtedness $ 781,916 $ 629,308 (1) As of December 31, 2019, borrowings under the Revolving Credit Facility, as described below, bear interest at the option of Columbia Property Trust at an alternate base rate, plus an applicable margin ranging from 0.00% to 0.45% for base-rate borrowings, or at LIBOR, as defined in the credit agreement, plus an applicable margin ranging from 0.775% to 1.45% for LIBOR-based borrowings, based on Columbia Property Trust's applicable credit rating. (2) Columbia Property Trust is party to an interest rate swap agreement with a notional amount of $300.0 million, which effectively fixes its interest rate on the $300 Million Term Loan, as further described below, at 2.55% and terminates on August 13, 2024. This interest rate swap agreement qualifies for hedge accounting treatment; therefore, changes in the fair value are recorded as a market value adjustment to interest rate swap in the accompanying consolidated statement of other comprehensive income.
Aggregate Maturities of Columbia Property Trust's Line of Credit and Notes Payable	The following table summarizes the aggregate maturities of Columbia Property Trust's line of credit and notes payable as of December 31, 2019 (in thousands): 2020 $ — 2021 — 2022 150,000 2023 334,000 2024 300,000 Thereafter — Total $ 784,000

Stockholders' Equity and Part_2

Stockholders' Equity and Partner's Capital (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Summary of the Activity of the Employee Stock Grants	Below is a summary of the employee awards issued under the LTI Plan for 2019, 2018, and 2017: Restricted Shares RSUs Shares Estimated Fair Value (1) Units Estimated Fair Value (2) Unvested as of January 1, 2017 256 $ 22.62 — $ — Granted 333 $ 21.59 331 $ 18.78 Vested (193) $ 22.42 — $ — Forfeited (7) $ 21.81 (2) $ 19.01 Unvested as of December 31, 2017 389 $ 21.85 329 $ — Granted 139 $ 22.97 206 $ 20.55 Vested (153) $ 22.13 (70) $ 19.47 Forfeited — $ — (11) $ 18.60 Unvested as of December 31, 2018 375 $ 22.15 454 $ 19.37 Granted 176 $ 19.36 257 $ 17.66 Vested (165) $ 21.99 (121) $ 19.08 Forfeited (12) $ 20.66 (6) $ 18.67 Unvested as of December 31, 2019 374 (3) $ 20.96 584 (3) $ 18.86 (1) Reflects the weighted-average grant-date fair value using the market closing price on the date of the grant. (2) Reflects the weighted-average grant-date fair value using a Monte Carlo valuation. (3) As of December 31, 2019, Columbia Property Trust expects approximately 360,000 of the 374,000 unvested restricted shares to ultimately vest and approximately 562,000 of the 584,000 unvested RSUs to ultimately vest, assuming a forfeiture rate of 4%, which was determined based on peer company data, adjusted for the specifics of the LTI Plan.
Summary of Shares Granted to Independent Directors	During 2019, 2018, and 2017, Columbia Property Trust granted the following equity retainers: Date of Grant Shares Grant-Date Fair Value (1) 2019 Director Grants: May 14, 2019 28,000 $ 22.13 2018 Director Grants: May 14, 2018 31,743 $ 22.20 2017 Director Grants: January 3, 2017 8,279 $ 21.58 May 2, 2017 33,581 $ 22.57 November 27, 2017 (2) 1,596 $ 23.07 (1) Columbia Property Trust determined the grant-date fair value using the market closing price on the date of the grant. (2) In November 2017, a new director was appointed to the board of directors of Columbia Property Trust. The new director received a pro-rated annual equity retainer grant at appointment.
Summary of Incurred Stock-Based Compensation Expense	Columbia Property Trust incurred stock-based compensation expense related to the following events (in thousands): 2019 2018 2017 Amortization of unvested LTI Plan awards $ 3,282 $ 3,800 $ 4,098 Future employee awards (1) 2,720 2,461 2,509 Issuance of shares to independent directors 620 705 973 Total stock-based compensation expense $ 6,622 $ 6,966 $ 7,580 (1) Reflects amortization of LTI Plan awards for service during the current period, for which shares will be issued in future periods.

Supplemental Disclosure of Nonc

Supplemental Disclosure of Noncash Investing and Financing Activities (Tables)	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Schedule of Other Significant Noncash Transactions	Outlined below are significant noncash investing and financing activities for Columbia Property Trust, Inc. for the years ended December 31, 2019, 2018, and 2017 (in thousands): Years Ended December 31, 2019 2018 2017 Investment in real estate funded with other assets $ — $ 617 $ 311 Deposits applied to sales of real estate $ — $ — $ 10,000 Other assets assumed upon acquisition $ 6 $ 259 $ 1,014 Other liabilities assumed upon acquisition $ 137 $ 664 $ 268 Real estate assets transferred to unconsolidated joint venture $ — $ — $ 558,122 Other assets transferred to unconsolidated joint venture $ — $ — $ 43,700 Other liabilities transferred to unconsolidated joint venture $ — $ — $ 21,347 Extinguishment of 263 Shuman Boulevard mortgage note by transferring property to lender $ — $ 49,000 $ — Settlement of capital lease obligation with related development authority bonds $ — $ 120,000 $ — Amortization of net discounts on debt $ 180 $ 180 $ 180 Accrued investments in unconsolidated joint ventures $ 198 $ 386 $ — Accrued capital expenditures and deferred lease costs $ 12,944 $ 15,145 $ 25,069 Operating lease liability recorded at adoption of ASC 842 $ 34,791 $ — $ — Accrued dividends payable $ 24,209 $ 23,340 $ 23,961 Cumulative-effect adjustment to equity for the adoption of ASU 2017-05 and 2014-09 $ — $ 358,098 $ — Market value adjustment to interest rate swaps that qualify for hedge accounting treatment $ (3,445) $ 1,441 $ 1,786 Common stock issued to employees and directors, and amortized (net of income tax witholdings) $ 6,622 $ 6,966 $ 7,580

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Schedule of Future Minimum Lease Payments To Be Made	As of December 31, 2019, the future minimum lease payments to be made by Columbia Property Trust under its operating lease are as follows (in thousands): 2020 $ 728 2021 760 2022 793 2023 67 2024 — Thereafter — Total lease payments 2,348 Less: interest expense (162) Present value of lease liabilities $ 2,186 Weighted-average remaining lease term (years) 3.1 years Weighted-average discount rate 4.5 %
Summary of Impact of Operating Leases on Consolidated Balance Sheet	Columbia Property Trust's operating leases had the following impacts on the consolidated balance sheet as of December 31, 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Assets: Total operating lease assets $ 27,843 $ 1,627 $ 29,470 Liabilities: Total operating lease liabilities $ — $ 2,186 $ 2,186
Summary of Impact of Operating Leases on Statements of Operations and Statements of Cash Flows	Columbia Property Trust's operating leases had the following impacts on the consolidated statements of operations for 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Property operating costs $ 2,165 $ — $ 2,165 General and administrative – corporate — 580 580 Total operating lease expenses $ 2,165 $ 580 $ 2,745 Columbia Property Trust's operating leases had the following impacts on the consolidated statements of cash flows for the 2019 (in thousands): Ground Leases Office Lease Total Operating Leases Cash paid for operating lease liabilities included in cash flows from operations $ (1,329) $ (697) $ (2,026)
Summary of Fixed and Variable Revenues	Fixed and variable payments for 2019 are as follows (in thousands): Fixed payments $ 250,077 Variable payments 26,072 Total lease revenues $ 276,149
Schedule of Future Minimum Lease Payments To Be Received	As of December 31, 2019, the future minimum fixed lease payments due to Columbia Property Trust under non-cancelable operating leases are as follows (thousands): 2020 $ 223,249 2021 224,999 2022 216,210 2023 205,955 2024 197,846 Thereafter 1,028,119 Total $ 2,096,378

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Income Tax Basis Net Income Reconciliation	Columbia Property Trust's income tax basis net income during 2019, 2018, and 2017 (in thousands) follows: 2019 2018 2017 GAAP basis financial statement net income attributable to common stockholders $ 9,197 $ 9,491 $ 176,041 Increase (Decrease) in Net Income Resulting From: Depreciation and amortization expense for financial reporting purposes in excess of amounts for income tax purposes 41,648 43,753 33,918 Rental income accrued for financial reporting purposes in excess of (less than) amounts for income tax purposes (10,373) 7,145 (38,426) Net amortization of above-/below-market lease intangibles for financial reporting purposes less than amounts for income tax purposes (5,107) (5,990) (6,091) Interest expense for financial reporting purposes in excess of amounts for income tax purposes 5,852 — — Bad debt expense for financial reporting purposes less than (in excess of) amounts for income tax purposes 1 4 (31) Income from unconsolidated joint ventures for financial reporting purposes in excess of amount for income tax purposes 15,224 16,654 13,902 Gains or losses on disposition of real property for financial reporting purposes that are more favorable than amounts for income tax purposes (57,284) 79,376 (126,770) Other expenses or revenues for financial reporting purposes in excess (less than) of amounts for income tax purposes 37,912 (32,342) 11,331 Income tax basis net income, prior to dividends-paid deduction $ 37,070 $ 118,091 $ 63,874
Schedule of Distributions to Common Stockholders	Columbia Property Trust's distributions per common share are summarized as follows: 2019 2018 2017 Ordinary income 53.1 % 100.0 % 58.5 % Capital gains — % — % — % Return of capital 46.9 % — % 41.5 % Total 100.0 % 100.0 % 100.0 %
Schedule of Income Taxes	The income taxes recorded by the TRS Entities for the years ended December 31, 2019, 2018, and 2017, are as follows: Years Ended December 31, 2019 2018 2017 Federal income tax $ 14 $ 63 $ 188 State income tax 6 (26) 38 Total income tax $ 20 $ 37 $ 226

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings per Share	The following table reconciles the numerator for the basic and diluted earnings-per-share computations shown on the consolidated statements of income (in thousands): 2019 2018 2017 Net income attributable to common stockholders $ 9,197 $ 9,491 $ 176,041 Distributions paid on unvested shares (310) (296) (337) Net income attributable to common stockholders used to calculate basic and diluted earnings per share $ 8,887 $ 9,195 $ 175,704 The following table reconciles the denominator for the basic and diluted earnings-per-share computations shown on the consolidated statements of income (in thousands): 2019 2018 2017 Weighted-average common shares – basic 116,261 117,888 120,795 Plus Incremental Weighted-Average Shares from Time-Vested Conversions Less Assumed Share Repurchases: Previously granted LTI Plan awards, unvested 114 104 116 Future LTI Plan awards 83 319 248 Weighted-average common shares – diluted 116,458 118,311 121,159

Quarterly Results (Unaudited) (

Quarterly Results (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Presented below is a summary of the unaudited quarterly financial information for the years ended December 31, 2019 and 2018 (in thousands, except per-share data): 2019 First Second Quarter Third Quarter Fourth Quarter Revenues $ 75,433 $ 72,730 $ 71,949 $ 68,725 Net income (loss) attributable to common stockholders $ 3,513 $ 47,747 (1) $ (20,286) (2) $ (21,777) (3) Net income (loss) attributable to common stockholders per share – basic (4) $ 0.03 $ 0.41 $ (0.17) $ (0.19) Net income (loss) attributable to common stockholders per share – diluted (4) $ 0.03 $ 0.41 $ (0.17) $ (0.19) Dividends declared per share $ 0.20 $ 0.20 $ 0.20 $ 0.21 2018 First Second Quarter Third Quarter Fourth Quarter Revenues $ 73,710 $ 75,370 $ 73,340 $ 75,523 Net income (loss) attributable to common stockholders $ 1,498 $ (3,439) (5) $ 6,429 $ 5,003 Net income (loss) attributable to common stockholders – basic (4) $ 0.01 $ (0.03) $ 0.05 $ 0.04 Net income (loss) attributable to common stockholders – diluted (4) $ 0.01 $ (0.03) $ 0.05 $ 0.04 Dividends declared per share $ 0.20 $ 0.20 $ 0.20 $ 0.20 (1) Net income attributable to common stockholders for the second quarter of 2019 includes a gain on sale of real estate assets of $41.9 million, as described in Note 3, Real Estate Transactions. (2) Net loss attributable to common stockholders for the third quarter of 2019 includes an impairment loss on real estate of $23.4 million related to sales of real estate assets, as described in Note 3, Real Estate Transactions. (3) Net loss attributable to common stockholders for the third quarter of 2019 includes an impairment loss on real estate of $20.6 million related to sales of real estate assets, as described in Note 2, Summary of Significant Accounting Policies. (4) Quarterly net income (loss) per share – basic and diluted is calculated based on quarterly basic and diluted weighted-average shares outstanding, respectively. (5) Net loss attributable to common stockholders for the second quarter of 2018 includes an impairment loss on real estate of $30.8 million related to sales of real estate assets, as described in Note 3, Real Estate Transactions , and a gain on extinguishment of debt of $24.0 million, related to the settlement of a mortgage note, as described in Note 5 , Line of Credit and Notes Payable.

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Reconciliation of Revenue from Segments to Consolidated	The following table presents property operating revenues by geographic reportable segment (in thousands): For the Years Ended December 31, 2019 2018 2017 New York (1) $ 157,244 $ 158,077 $ 123,280 San Francisco (2) 114,295 105,947 105,550 Washington, D.C. (3) 58,200 57,274 36,934 Boston 14,285 13,441 11,559 Los Angeles 7,754 7,783 7,462 All other office markets 41,321 57,395 59,263 Total office segments 393,099 399,917 344,048 Hotel — — 1,328 Corporate 3,137 3,165 579 Total $ 396,236 $ 403,082 $ 345,955 (1) Includes operating revenues for 101 Franklin Street from December 2, 2019 through December 31, 2019; and for one unconsolidated property, 114 Fifth Avenue, based on Columbia Property Trust's ownership interest (49.5%) from July 6, 2017 (acquisition date) through December 31, 2019. (2) Includes operating revenues for two unconsolidated properties, 333 Market Street and University Circle, based on Columbia Property Trust's ownership interests: 100.0% from January 1, 2017 through July 5, 2017; 77.5% from July 6, 2017 through January 31, 2018; and 55.0% from February 1, 2018 through December 31, 2019. (3) Includes operating revenues for two unconsolidated properties, Market Square and 1800 M Street, based on Columbia Property Trust's ownership interests: 51.0% for the Market Square for all periods presented; 55.0% for 1800 M Street from October 11, 2017 (acquisition date) through December 31, 2019. A reconciliation of GAAP revenues to operating revenues is presented below (in thousands): For the Years Ended December 31, 2019 2018 2017 Total revenues $ 288,837 $ 297,943 $ 289,000 Operating revenues included in income (loss) from unconsolidated joint ventures (1) 114,943 112,523 60,737 Less: asset and property management fee income (2) (7,544) (7,384) (3,782) Total property operating revenues $ 396,236 $ 403,082 $ 345,955 (1) Columbia Property Trust records its interest in properties held through unconsolidated joint ventures using the equity method of accounting, and reflects its interest in the operating revenues of these properties in income (loss) from unconsolidated joint ventures in the accompanying consolidated statements of operations. (2) See Note 11, Non-Lease Revenues , of the accompanying consolidated financial statements.
Schedule of Segment Reporting Information, by Segment	The following table presents net operating income by geographic reportable segment (in thousands): For the Years Ended December 31, 2019 2018 2017 New York (1) $ 93,112 $ 94,765 $ 73,893 San Francisco (2) 83,305 79,354 76,163 Washington, D.C. (3) 33,953 34,750 18,496 Boston 7,539 7,205 5,380 Los Angeles 4,601 4,590 4,529 All other office markets 35,428 51,638 52,153 Total office segments 257,938 272,302 230,614 Hotel — — (913) Corporate (904) (803) (826) Total $ 257,034 $ 271,499 $ 228,875 (1) Includes NOI for the following unconsolidated properties based on Columbia Property Trust's ownership interest: • 114 Fifth Avenue: (49.5%) from July 6, 2017 (acquisition date) through December 31, 2019 • 799 Broadway: (49.7%) from October 3, 2018 (acquisition date) through December 31, 2019 (2) Includes NOI for the following unconsolidated properties based on Columbia Property Trust's ownership interests: • 333 Market Street and University Circle: (100.0%) from January 1, 2017 through July 5, 2017 • 333 Market Street and University Circle: (77.5%) from July 6, 2017 through January 31, 2018 • 333 Market Street and University Circle: (55.0%) from February 1, 2018 through December, 2019 (3) Includes NOI for the following unconsolidated properties based on Columbia Property Trust's ownership interest: • Market Square: (51.0%) for all periods presented • 1800 M Street: (55.0%) from October 11, 2017 (acquisition date) through December 31, 2019 A reconciliation of GAAP net income to NOI is presented below (in thousands): For the Years Ended December 31, 2019 2018 2017 Net income attributable to common stockholders $ 9,197 $ 9,491 $ 176,041 Depreciation 78,292 81,795 80,394 Amortization 27,908 32,554 32,403 Impairment loss on real estate assets 43,941 30,812 — General and administrative – corporate 32,779 32,979 34,966 General and administrative – joint venture 3,567 3,108 1,454 Pre-acquisition costs 6,398 — — Net interest expense 42,997 56,477 58,187 Interest income from development authority bonds — (6,871) (7,200) (Gain) loss on extinguishment of debt — (23,340) 325 Income tax expense 21 37 (213) Asset and property management fee income (7,544) (7,384) (3,782) Adjustments included in loss from unconsolidated joint venture 61,634 62,603 31,818 Gain on sale of unconsolidated joint venture interest — (762) — Gains on sales of real estate assets (42,030) — (175,518) Adjustment attributable to noncontrolling interests (126) — — Net operating income $ 257,034 $ 271,499 $ 228,875

Organization (Details)

Organization (Details) ft² in Millions	Dec. 31, 2019ft²property
Real Estate
Square feet of commercial space | ft²	7.3
Leased office space of owned properties (as a percent)	97.10%
Office Building
Real Estate
Number of properties	17
Number of properties under development or redevelopment	3
Office Building | Wholly Owned Properties
Real Estate
Number of properties	13
Office Building | Corporate Joint Venture
Real Estate
Number of properties	7

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details)	Sep. 26, 2019USD ($)	Dec. 31, 2019USD ($)bond$ / sharesshares	Sep. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Dec. 31, 2019USD ($)bond$ / sharesshares	Dec. 31, 2018USD ($)bond$ / shares	Dec. 31, 2017USD ($)	May 25, 2018USD ($)
Property, Plant and Equipment [Line Items]
Interest capitalized to investments in unconsolidated joint ventures					$ 5,100,000	$ 3,800,000
Impairment loss on real estate assets			$ 23,400,000	$ 30,800,000	43,941,000	30,812,000	$ 0
Accumulated depreciation of lease assets		$ 58,659,000			$ 58,659,000	84,881,000
Cash equivalent maturity period (in months)					3 months
Provision for doubtful accounts					$ (22,000)	63,000
Amortization of deferred lease costs					6,300,000	5,500,000	5,200,000
Amortization of lease incentives					700,000	2,100,000	3,300,000
Deferred financing costs		$ 2,084,000			$ 2,084,000	$ 2,692,000
Number of series of bonds | bond		2			2	2
Common stock, par value (in dollars per share) | $ / shares		$ 0.01			$ 0.01	$ 0.01
Preferred stock shares authorized | shares		100,000,000			100,000,000
Preferred stock par value (in dollars per share) | $ / shares		$ 0.01			$ 0.01
Minimum requirement to distribute taxable income (percent)		90.00%			90.00%
Estimated gain to be reclassified from AOCI as reduction to interest expense over next 12 months		$ 900,000			$ 900,000
Limit on investments in taxable real estate investment trusts (percent)		20.00%			20.00%
Intangible below market ground lease assets
Property, Plant and Equipment [Line Items]
Gross intangible assets						$ 32,600,000
Accumulated depreciation of lease assets						2,600,000
Term Loans
Property, Plant and Equipment [Line Items]
Deferred financing costs		$ 2,084,000			$ 2,084,000	2,692,000
Unsecured Debt
Property, Plant and Equipment [Line Items]
Deferred financing costs		$ 3,552,000			$ 3,552,000	$ 4,158,000
Number of series of bonds | bond		2			2	2
Unsecured Debt | 2026 Bonds Payable
Property, Plant and Equipment [Line Items]
Debt face amount		$ 350,000,000			$ 350,000,000	$ 350,000,000
Debt term					10 years	10 years
Stated interest rate		3.65%			3.65%	3.65%
Discount rate of face value of issued debt instrument (percent)		99.626%			99.626%	99.626%
Unsecured Debt | 2025 Bonds Payable
Property, Plant and Equipment [Line Items]
Debt face amount		$ 350,000,000			$ 350,000,000	$ 350,000,000
Debt term					10 years	10 years
Stated interest rate		4.15%			4.15%	4.15%
Discount rate of face value of issued debt instrument (percent)		99.859%			99.859%	99.859%
Common Stock | Stock Repurchase Program
Property, Plant and Equipment [Line Items]
Common stock, par value (in dollars per share) | $ / shares		$ 0.01			$ 0.01
Stock repurchase program, amount available for repurchase		$ 166,500,000			$ 166,500,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Pasedena Corporate Park
Property, Plant and Equipment [Line Items]
Impairment loss on real estate assets		20,600,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | 222 East 41st Street
Property, Plant and Equipment [Line Items]
Impairment loss on real estate assets				$ 30,800,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Lindbergh Center
Property, Plant and Equipment [Line Items]
Impairment loss on real estate assets	$ 23,400,000		23,400,000
Level 1 | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Pasedena Corporate Park
Property, Plant and Equipment [Line Items]
Real estate investment, fair value		$ 74,500,000			74,500,000
Level 1 | Disposal Group, Disposed of by Sale, Not Discontinued Operations | 222 East 41st Street
Property, Plant and Equipment [Line Items]
Real estate investment, fair value								$ 284,600,000
Level 1 | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Lindbergh Center
Property, Plant and Equipment [Line Items]
Real estate investment, fair value			$ 181,000,000
Corporate Joint Venture
Property, Plant and Equipment [Line Items]
Interest capitalized to investments in unconsolidated joint ventures					1,300,000	$ 200,000
Interest Expense
Property, Plant and Equipment [Line Items]
Amortization of deferred financing costs					$ 2,400,000	$ 2,900,000	$ 2,800,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives for Real Estate (Details)	12 Months Ended
	Dec. 31, 2019
Office Lease
Real Estate Properties [Line Items]
Estimated useful life of assets (in years)	40 years
Building Improvements | Minimum
Real Estate Properties [Line Items]
Estimated useful life of assets (in years)	5 years
Building Improvements | Maximum
Real Estate Properties [Line Items]
Estimated useful life of assets (in years)	25 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Assets and Liabilities Held for sale (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Land	$ 57,117
Buildings and improvements, less accumulated depreciation of $80,543	157,701
Construction in progress	138
Total real estate assets held for sale, net	214,956
Tenant receivables	156
Straight-line rent receivable	12,591
Prepaid expenses and other assets	334
Deferred lease costs, less accumulated amortization of $10,222	10,836
Total other assets held for sale, net	23,917	$ 0
Accounts payable, accrued expenses, and accrued capital expenditures	1,151
Deferred income	1,903
Total liabilities held for sale	3,054
Accumulated depreciation	80,543
Accumulated amortization	$ 10,222

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Schedule of Intangible Assets & Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Intangible Lease Assets
Intangible lease assets, accumulated amortization	$ (58,659)	$ (84,881)
Intangible lease origination costs, accumulated amortization	(33,731)	(65,348)
Intangible lease assets, net	61,025	98,540
Intangible lease origination costs, net	27,971	34,092
Intangible Below-Market In-Place Lease Liabilities
Intangible below-market in-place lease liabilities, gross	36,966	42,847
Intangible below-market in-place lease liabilities, accumulated amortization	(15,127)	(21,766)
Below market lease, net	21,839	21,081
Amortization of intangible lease assets
Amortization of intangible lease assets	27,908	32,554	$ 32,403
Amortization of below market lease liabilities	5,395	6,851	6,883
Above-Market In-Place Lease Assets
Intangible Lease Assets
Intangible lease assets, gross	2,481	3,174
Intangible lease assets, accumulated amortization	(1,202)	(1,060)
Intangible lease assets, net	1,279	2,114
Amortization of intangible lease assets
Amortization of intangible lease assets	288	228	519
Absorption Period Costs
Intangible Lease Assets
Intangible lease assets, gross	117,203	147,668
Intangible lease assets, accumulated amortization	(57,457)	(81,220)
Intangible lease assets, net	59,746	66,448
Amortization of intangible lease assets
Amortization of intangible lease assets	13,511	17,137	16,807
Intangible Lease Origination Costs
Intangible Lease Assets
Intangible lease origination costs, gross	61,702	99,440
Intangible lease origination costs, accumulated amortization	(33,731)	(65,348)
Intangible lease origination costs, net	27,971	34,092
Amortization of intangible lease assets
Amortization of intangible lease assets	$ 7,398	$ 9,660	$ 10,124

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Schedule of Net Below-Market Lease Asset Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Intangible Lease Assets
Intangible lease assets, net	$ 61,025	$ 98,540
Intangible lease origination costs, net	27,971	34,092
Intangible Below-Market In-Place Lease Liabilities
2020	5,483
2021	3,191
2022	2,910
2023	2,336
2024	1,990
Thereafter	5,929
Below market lease, net	$ 21,839	21,081
Weighted - average amortization period (in years)	5 years 3 months 18 days
Above-Market In-Place Lease Assets
Intangible Lease Assets
2020	$ 172
2021	172
2022	172
2023	172
2024	172
Thereafter	419
Intangible lease assets, net	$ 1,279	2,114
Weighted - average amortization period (in years)	6 years 7 months 6 days
Absorption Period Costs
Intangible Lease Assets
2020	$ 12,871
2021	9,328
2022	7,959
2023	6,455
2024	5,594
Thereafter	17,539
Intangible lease assets, net	$ 59,746	66,448
Weighted - average amortization period (in years)	5 years
Intangible Lease Origination Costs
Intangible Lease Assets
2020	$ 5,866
2021	4,516
2022	3,429
2023	2,903
2024	2,586
Thereafter	8,671
Intangible lease origination costs, net	$ 27,971	$ 34,092
Weighted - average amortization period (in years)	4 years 10 months 24 days

Summary of Significant Accoun_9

Summary of Significant Accounting Policies (Interest Rate Swaps) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)interestRateSwap	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Summary of Derivative Instruments Impact on Results of Operations [Abstract]
Market value adjustment to interest rate swaps designated as hedging instruments and included in other comprehensive income (loss)	$ (3,445)	$ 1,441	$ 1,786
Interest Rate Contract
Derivatives, Fair Value [Line Items]
Number of interest rate swaps | interestRateSwap	2
Notional amount	$ 450,000
Interest Rate Contract | Prepaid Expenses and Other Assets
Derivative, Fair Value, Net [Abstract]
Derivative designated as hedging instruments, interest rate contracts	551	2,344
Interest Rate Contract | Accounts Payable
Derivative, Fair Value, Net [Abstract]
Derivative designated as hedging instruments, interest rate contracts	$ 1,652	$ 0

Real Estate Transactions - Sche

Real Estate Transactions - Schedule of Properties Acquired (Details) - USD ($) $ in Thousands	Dec. 09, 2019	Dec. 02, 2019	Oct. 24, 2018	Oct. 03, 2018	Nov. 28, 2017	Oct. 11, 2017	Jul. 06, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Purchase price								$ 453,128	$ 23,034	$ 604,769
Purchase price of joint venture								$ 17,134	$ 38,763	$ 369,043
201 California Street
Business Acquisition [Line Items]
Ownership percentage	100.00%
Purchase price	$ 238,900
101 Franklin Street
Business Acquisition [Line Items]
Ownership percentage		92.50%
Purchase price		$ 205,500
Lindbergh Center – Retail
Business Acquisition [Line Items]
Ownership percentage			100.00%
Purchase price			$ 23,000
149 Madison Avenue
Business Acquisition [Line Items]
Ownership percentage					100.00%
Purchase price					$ 87,700
249 West 17th Street & 218 West 18th Street
Business Acquisition [Line Items]
Ownership percentage						100.00%
Purchase price						$ 514,100
Corporate Joint Venture | 799 Broadway Joint Venture
Business Acquisition [Line Items]
Ownership percentage				49.70%				49.70%
Purchase price of joint venture				$ 30,200
Corporate Joint Venture | 1800 M Street Joint Venture
Business Acquisition [Line Items]
Ownership percentage						55.00%		55.00%
Purchase price						$ 421,000
Purchase price of joint venture						$ 231,550
Corporate Joint Venture | 114 Fifth Avenue
Business Acquisition [Line Items]
Ownership percentage							49.50%	49.50%
Purchase price of joint venture							$ 108,900

Real Estate Transactions - Narr

Real Estate Transactions - Narrative (Details) ft² in Thousands

Dec. 09, 2019USD ($)ft²Tenant

Dec. 02, 2019USD ($)ft²

Oct. 24, 2018USD ($)ft²

Oct. 03, 2018USD ($)ft²

Nov. 28, 2017USD ($)ft²

Oct. 11, 2017USD ($)ft²Tenant

Jul. 06, 2017USD ($)ft²

Dec. 31, 2019USD ($)ft²

Dec. 31, 2017USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2019USD ($)ft²

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Business Acquisition [Line Items]

Square feet of space | ft²

7,300

7,300

Payments to acquire real estate

$ 453,128,000

$ 23,034,000

$ 604,769,000

Purchase price of joint venture

17,134,000

38,763,000

369,043,000

Real estate assets transferred to unconsolidated joint venture

0

$ 0

$ 558,122,000

201 California Street

Business Acquisition [Line Items]

Square feet of space | ft²

252

Percent leased

99.00%

Ownership percentage

100.00%

Number of tenants | Tenant

34

Revenue of acquiree since acquisition date

$ 1,400,000

Earnings (loss) of acquiree since acquisition date

$ 100,000

Payments to acquire real estate

$ 238,900,000

101 Franklin Street

Business Acquisition [Line Items]

Square feet of space | ft²

235

Ownership percentage

92.50%

Earnings (loss) of acquiree since acquisition date

$ 37,000

Payments to acquire real estate

$ 205,500,000

Lindbergh Center – Retail

Business Acquisition [Line Items]

Ownership percentage

100.00%

Payments to acquire real estate

$ 23,000,000

149 Madison Avenue

Business Acquisition [Line Items]

Ownership percentage

100.00%

Revenue of acquiree since acquisition date

$ 10,300

Earnings (loss) of acquiree since acquisition date

$ 9,200

Payments to acquire real estate

$ 87,700,000

249 West 17th Street

Business Acquisition [Line Items]

Percent leased

100.00%

Number of tenants | Tenant

4

Revenue of acquiree since acquisition date

$ 5,900,000

Earnings (loss) of acquiree since acquisition date

1,800,000

218 West 18th Street

Business Acquisition [Line Items]

Percent leased

100.00%

Number of tenants | Tenant

7

Revenue of acquiree since acquisition date

3,000,000

Earnings (loss) of acquiree since acquisition date

$ 800,000

Ancillary Retail And Office Building | Lindbergh Center – Retail

Business Acquisition [Line Items]

Square feet of space | ft²

147

Office Building | 149 Madison Avenue

Business Acquisition [Line Items]

Square feet of space | ft²

127

Office Building | 249 West 17th Street

Business Acquisition [Line Items]

Square feet of space | ft²

281

Office Building | 218 West 18th Street

Business Acquisition [Line Items]

Square feet of space | ft²

166

Customer concentration risk | First Republic Bank | 201 California Street

Business Acquisition [Line Items]

Concentration risk percentage

13.00%

Customer concentration risk | Dow Jones & Company, Inc. | 201 California Street

Business Acquisition [Line Items]

Concentration risk percentage

12.00%

Customer concentration risk | Cooper, White & Cooper, LLP | 201 California Street

Business Acquisition [Line Items]

Concentration risk percentage

12.00%

Customer concentration risk | Twitter | 249 West 17th Street

Business Acquisition [Line Items]

Concentration risk percentage

76.00%

Customer concentration risk | Room & Board | 249 West 17th Street

Business Acquisition [Line Items]

Concentration risk percentage

21.00%

Customer concentration risk | Red Bull North America | 218 West 18th Street

Business Acquisition [Line Items]

Concentration risk percentage

25.00%

Customer concentration risk | Company 3 | 218 West 18th Street

Business Acquisition [Line Items]

Concentration risk percentage

18.00%

Customer concentration risk | SY Partners | 218 West 18th Street

Business Acquisition [Line Items]

Concentration risk percentage

16.00%

Customer concentration risk | SAE | 218 West 18th Street

Business Acquisition [Line Items]

Concentration risk percentage

16.00%

Corporate Joint Venture | 799 Broadway Joint Venture

Business Acquisition [Line Items]

Ownership percentage

49.70%

49.70%

49.70%

Purchase price of joint venture

$ 30,200,000

Corporate Joint Venture | 799 Broadway Joint Venture | Office Building

Business Acquisition [Line Items]

Square feet of space | ft²

182

Corporate Joint Venture | 1800 M Street Joint Venture

Business Acquisition [Line Items]

Percent leased

94.00%

Ownership percentage

55.00%

55.00%

55.00%

Payments to acquire real estate

$ 421,000,000

Purchase price of joint venture

$ 231,550,000

Corporate Joint Venture | 1800 M Street Joint Venture | Office Building

Business Acquisition [Line Items]

Square feet of space | ft²

581

Corporate Joint Venture | 114 Fifth Avenue

Business Acquisition [Line Items]

Square feet of space | ft²

352

Percent leased

100.00%

Ownership percentage

49.50%

49.50%

49.50%

Purchase price of joint venture

$ 108,900,000

Corporate Joint Venture | 799 Broadway Joint Venture

Business Acquisition [Line Items]

Proceeds from construction loan

$ 97,000,000

$ 113,200,000

Corporate Joint Venture | Normandy | 799 Broadway Joint Venture

Business Acquisition [Line Items]

Real estate assets transferred to unconsolidated joint venture

145,500,000

Corporate Joint Venture | Allianz | 1800 M Street Joint Venture

Business Acquisition [Line Items]

Ownership percentage

45.00%

Corporate Joint Venture | Allianz | 114 Fifth Avenue

Business Acquisition [Line Items]

Ownership percentage

49.50%

Corporate Joint Venture | L & L Holding Company | 114 Fifth Avenue

Business Acquisition [Line Items]

Ownership percentage

1.00%

Construction Loan Payable | Corporate Joint Venture | 799 Broadway Joint Venture

Business Acquisition [Line Items]

Line of credit facility, maximum borrowing capacity

$ 187,000,000

Real Estate Transactions - Purc

Real Estate Transactions - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 09, 2019	Dec. 02, 2019	Nov. 28, 2017	Oct. 11, 2017
Business Acquisition [Line Items]
Total purchase price	$ 246,308	$ 206,645
201 California Street
Business Acquisition [Line Items]
Land	77,833
Building and improvements	157,513
Intangible below market lease liability	$ (8,064)
Ownership percentage	100.00%
101 Franklin Street
Business Acquisition [Line Items]
Land		57,145
Building and improvements		149,500
Intangible below market lease liability		$ 0
Ownership percentage		92.50%
149 Madison Avenue
Business Acquisition [Line Items]
Land			$ 59,112
Building and improvements			28,989
Intangible below market lease liability			0
Total purchase price			$ 88,101
Ownership percentage			100.00%
249 West 17th Street
Business Acquisition [Line Items]
Land				$ 113,149
Building and improvements				194,109
Intangible below market lease liability				(7,131)
Total purchase price				340,597
218 West 18th Street
Business Acquisition [Line Items]
Land				43,836
Building and improvements				126,957
Intangible below market lease liability				(11,757)
Total purchase price				175,324
Intangible lease assets | 201 California Street
Business Acquisition [Line Items]
Intangible lease assets	$ 13,241
Intangible lease assets | 101 Franklin Street
Business Acquisition [Line Items]
Intangible lease assets		$ 0
Intangible lease assets | 149 Madison Avenue
Business Acquisition [Line Items]
Intangible lease assets			$ 0
Intangible lease assets | 249 West 17th Street
Business Acquisition [Line Items]
Intangible lease assets				27,408
Intangible lease assets | 218 West 18th Street
Business Acquisition [Line Items]
Intangible lease assets				12,120
Intangible lease origination costs | 201 California Street
Business Acquisition [Line Items]
Intangible lease assets	$ 5,785
Intangible lease origination costs | 101 Franklin Street
Business Acquisition [Line Items]
Intangible lease assets		$ 0
Intangible lease origination costs | 149 Madison Avenue
Business Acquisition [Line Items]
Intangible lease assets			$ 0
Intangible lease origination costs | 249 West 17th Street
Business Acquisition [Line Items]
Intangible lease assets				13,062
Intangible lease origination costs | 218 West 18th Street
Business Acquisition [Line Items]
Intangible lease assets				$ 4,168

Real Estate Transactions - Pro

Real Estate Transactions - Pro Forma (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisitions and Dispositions [Abstract]
Revenues	$ 304,756	$ 312,003	$ 319,064
Net income attributable to common stockholders of Columbia Property Trust	$ 17,600	$ 16,822	$ 183,318

Real Estate Transactions - Disp

Real Estate Transactions - Dispositions (Details) - USD ($)

Sep. 26, 2019

Apr. 15, 2019

May 30, 2018

May 29, 2018

Apr. 13, 2018

Feb. 02, 2018

Feb. 01, 2018

Jul. 06, 2017

Jan. 31, 2017

Jan. 06, 2017

Sep. 30, 2019

Jun. 30, 2019

Jun. 30, 2018

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Business Acquisition [Line Items]

Gain (Loss) on Sale

$ 41,900,000

Impairment loss on real estate assets

$ 23,400,000

$ 30,800,000

$ 43,941,000

$ 30,812,000

$ 0

Gain (loss) on extinguishment of debt

24,000,000

0

23,340,000

(325,000)

Net proceeds from the sale of investments in unconsolidated joint ventures

0

$ 235,083,000

$ 0

Key Center Tower & Marriot

Business Acquisition [Line Items]

Gain (Loss) on Sale

$ 22,500,000

Disposal Group, Disposed of by Sale, Not Discontinued Operations | Lindbergh Center

Business Acquisition [Line Items]

% Sold

100.00%

Sales Price

$ 187,000,000

Gain (Loss) on Sale

0

Impairment loss on real estate assets

23,400,000

$ 23,400,000

Disposal Group, Disposed of by Sale, Not Discontinued Operations | One & Three Glenlake

Business Acquisition [Line Items]

% Sold

100.00%

Sales Price

$ 227,500,000

Gain (Loss) on Sale

42,030,000

Adjustments for tenant improvement allowances and rent abatements

$ 33,600,000

Disposal Group, Disposed of by Sale, Not Discontinued Operations | 222 East 41st Street

Business Acquisition [Line Items]

% Sold

100.00%

Sales Price

$ 332,500,000

Gain (Loss) on Sale

0

Impairment loss on real estate assets

30,800,000

Disposal Group, Disposed of by Sale, Not Discontinued Operations | 263 Shuman Boulevard

Business Acquisition [Line Items]

% Sold

100.00%

Sales Price

$ 49,000,000

Gain (Loss) on Sale

24,039,000

Disposal Group, Disposed of by Sale, Not Discontinued Operations | University Circle & 333 Market Street

Business Acquisition [Line Items]

% Sold

22.50%

22.50%

Sales Price

$ 235,300,000

$ 234,000,000

Gain (Loss) on Sale

762,000

$ 102,365,000

Disposal Group, Disposed of by Sale, Not Discontinued Operations | Key Center Tower & Marriot

Business Acquisition [Line Items]

% Sold

100.00%

Sales Price

$ 267,500,000

Gain (Loss) on Sale

9,466,000

Proceeds from sale of real estate held-for-investment, gross

254,500,000

Note receivable

$ 13,000,000

Term of note receivable

10 years

Deferred gain on sale of property

$ 13,000,000

Disposal Group, Disposed of by Sale, Not Discontinued Operations | Houston Properties

Business Acquisition [Line Items]

% Sold

100.00%

Sales Price

$ 272,000,000

Gain (Loss) on Sale

$ 63,688,000

Revolving Credit Facility | $300 Million Bridge Loan

Business Acquisition [Line Items]

Repayments of debt

$ 46,000,000

Bridge Loan | $300 Million Bridge Loan

Business Acquisition [Line Items]

Repayments of debt

$ 180,000,000

180,000,000

$ 120,000,000

Bridge loan

$ 300,000,000

$ 300,000,000

Gain (loss) on extinguishment of debt

$ (300,000)

Mortgages | 263 Shuman Boulevard Building mortgage note

Business Acquisition [Line Items]

Extinguishment of debt

$ 49,000,000

Gain (loss) on extinguishment of debt

$ 24,000,000

San Francisco Joint Ventures | Corporate Joint Venture

Business Acquisition [Line Items]

Net proceeds from the sale of investments in unconsolidated joint ventures

$ 235,300,000

Ownership percentage

55.00%

San Francisco Joint Ventures | Corporate Joint Venture | Allianz

Business Acquisition [Line Items]

% Sold

22.50%

Additional ownership percentage acquired

22.50%

Net proceeds from the sale of investments in unconsolidated joint ventures

$ 234,000,000

Unconsolidated Joint Ventures -

Unconsolidated Joint Ventures - Summary of Financial Information for the Joint Ventures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 03, 2018	Oct. 11, 2017	Jul. 06, 2017
Schedule of Equity Method Investments [Line Items]
Interest capitalized	$ 5,100	$ 4,000	$ 300
Difference between carrying amount and underlying equity	279,200	282,000
Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Carrying Value of Investment	$ 1,054,460	1,071,353
Corporate Joint Venture | Market Square Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership Interest	51.00%
Carrying Value of Investment	$ 135,557	134,250
Corporate Joint Venture | University Circle Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership Interest	55.00%
Carrying Value of Investment	$ 283,633	292,951
Corporate Joint Venture | 333 Market Street Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership Interest	55.00%
Carrying Value of Investment	$ 269,638	273,783
Corporate Joint Venture | 114 Fifth Avenue
Schedule of Equity Method Investments [Line Items]
Ownership Interest	49.50%					49.50%
Carrying Value of Investment	$ 87,750	99,283
Corporate Joint Venture | 1800 M Street Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership Interest	55.00%				55.00%
Carrying Value of Investment	$ 233,196	237,333
Corporate Joint Venture | 799 Broadway Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership Interest	49.70%			49.70%
Carrying Value of Investment	$ 44,686	33,753
Interest capitalized	$ 1,300	$ 200

Unconsolidated Joint Ventures_2

Unconsolidated Joint Ventures (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Prepaid Expenses and Other Assets | Corporate Joint Venture
Related Party Transaction [Line Items]
Property management fees due to Columbia Property Trust	$ 600	$ 700
Asset and property management fee income/expenses
Related Party Transaction [Line Items]
Revenue	7,544	7,384	$ 3,782
Asset and property management fee income/expenses | Other Property Income | Corporate Joint Venture
Related Party Transaction [Line Items]
Revenue	$ 4,300	$ 4,200	$ 2,000

Unconsolidated Joint Ventures_3

Unconsolidated Joint Ventures (Condensed Balance Sheet Information) (Details) - Corporate Joint Venture $ in Thousands	Oct. 03, 2018USD ($)	Dec. 31, 2019USD ($)extension	Dec. 31, 2018USD ($)
Schedule of Equity Method Investments [Line Items]
Total Assets		$ 2,291,036	$ 2,176,751
Total Debt		434,550	420,392
Total Equity		1,441,218	1,467,334
Market Square Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Assets		582,747	582,176
Total Debt		324,815	324,762
Total Equity		241,719	241,581
University Circle Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Assets		216,546	224,746
Total Debt		0	0
Total Equity		212,656	219,390
333 Market Street Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Assets		367,652	375,884
Total Debt		0	0
Total Equity		352,385	360,915
114 Fifth Avenue
Schedule of Equity Method Investments [Line Items]
Total Assets		485,442	377,970
Total Debt		0	0
Total Equity		127,554	149,243
1800 M Street Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Assets		437,439	447,585
Total Debt		0	0
Total Equity		421,588	429,016
799 Broadway Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Assets		201,210	168,390
Total Debt		109,735	95,630
Total Equity		85,316	67,189
Blackstone Property Partners
Schedule of Equity Method Investments [Line Items]
Mortgage note transferred to joint venture		$ 325,000	$ 325,000
Stated interest rate		5.07%	5.07%
799 Broadway Joint Venture
Schedule of Equity Method Investments [Line Items]
Proceeds from construction loan	$ 97,000	$ 113,200
Deferred financing costs		3,500
Borrowing capacity		$ 187,000
Interest rate (as a percent)		4.00%
Basis spread (in points)		4.25%
Number of extension options | extension		2
Extension term		1 year

Unconsolidated Joint Ventures_4

Unconsolidated Joint Ventures (Condensed Income Statement Information) (Details) - Corporate Joint Venture - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Total Revenues	$ 201,632	$ 194,057	$ 102,244
Net Income (Loss)	20,996	19,943	(2,684)
Columbia Property Trust's Share of Net Income (Loss)	12,642	12,704	2,651
Market Square Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Revenues	47,737	44,815	41,749
Net Income (Loss)	(11,515)	(12,304)	(15,192)
Columbia Property Trust's Share of Net Income (Loss)	(5,873)	(6,275)	(7,747)
University Circle Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Revenues	44,427	43,581	19,386
Net Income (Loss)	24,251	23,776	9,826
Columbia Property Trust's Share of Net Income (Loss)	13,338	13,478	7,561
333 Market Street Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Revenues	28,170	27,006	12,971
Net Income (Loss)	14,929	14,620	6,948
Columbia Property Trust's Share of Net Income (Loss)	8,211	8,312	5,331
114 Fifth Avenue
Schedule of Equity Method Investments [Line Items]
Total Revenues	42,921	41,169	20,133
Net Income (Loss)	(10,674)	(10,256)	(4,885)
Columbia Property Trust's Share of Net Income (Loss)	(5,283)	(5,077)	(2,820)
1800 M Street Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Revenues	38,377	37,486	8,005
Net Income (Loss)	4,887	4,239	619
Columbia Property Trust's Share of Net Income (Loss)	2,688	2,332	326
799 Broadway Joint Venture
Schedule of Equity Method Investments [Line Items]
Total Revenues	0	0	0
Net Income (Loss)	(882)	(132)	0
Columbia Property Trust's Share of Net Income (Loss)	$ (439)	$ (66)	$ 0

Unconsolidated Joint Ventures_5

Unconsolidated Joint Ventures (Property and Asset Management Fees) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Asset and property management fee income	$ 7,500	$ 7,400	$ 3,800
Corporate Joint Venture
Schedule of Equity Method Investments [Line Items]
Asset and property management fee income	7,544	7,384	3,782
Corporate Joint Venture | Market Square Joint Venture
Schedule of Equity Method Investments [Line Items]
Asset and property management fee income	2,256	2,156	1,998
Corporate Joint Venture | University Circle Joint Venture
Schedule of Equity Method Investments [Line Items]
Asset and property management fee income	2,313	2,283	1,000
Corporate Joint Venture | 333 Market Street Joint Venture
Schedule of Equity Method Investments [Line Items]
Asset and property management fee income	819	784	367
Corporate Joint Venture | 1800 M Street Joint Venture
Schedule of Equity Method Investments [Line Items]
Asset and property management fee income	$ 2,156	$ 2,161	$ 417

Line of Credit and Notes Paya_3

Line of Credit and Notes Payable - Schedule of Long-Term Debt (excluding Bonds Payable) (Details) - USD ($)	Dec. 07, 2018	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Outstanding debt		$ 781,916,000	$ 629,308,000
Less: Deferred financing costs related to term loans		(2,084,000)	(2,692,000)
Total indebtedness		781,916,000	629,308,000
Credit Facilities | Revolving Credit Facility
Debt Instrument [Line Items]
Outstanding debt		334,000,000	482,000,000
Term Loans
Debt Instrument [Line Items]
Less: Deferred financing costs related to term loans		(2,084,000)	(2,692,000)
Term Loans | $300 Million Term Loan
Debt Instrument [Line Items]
Debt face amount	$ 300,000,000	300,000,000
Outstanding debt		$ 300,000,000	0
Effective interest rate		2.55%
Term Loans | $150 Million Term Loan
Debt Instrument [Line Items]
Debt face amount		$ 150,000,000
Outstanding debt		$ 150,000,000	$ 150,000,000
Effective interest rate		3.07%
Base Rate | Credit Facilities | Minimum | Revolving Credit Facility
Debt Instrument [Line Items]
Variable rate margin	0.00%
Base Rate | Credit Facilities | Maximum | Revolving Credit Facility
Debt Instrument [Line Items]
Variable rate margin	0.45%
Base Rate | Term Loans | Minimum | $300 Million Term Loan
Debt Instrument [Line Items]
Variable rate margin	0.00%
Base Rate | Term Loans | Maximum | $300 Million Term Loan
Debt Instrument [Line Items]
Variable rate margin	0.65%
London Interbank Offered Rate (LIBOR) | Credit Facilities | Revolving Credit Facility
Debt Instrument [Line Items]
Variable rate margin		0.90%
London Interbank Offered Rate (LIBOR) | Credit Facilities | Minimum | Revolving Credit Facility
Debt Instrument [Line Items]
Variable rate margin	0.775%
London Interbank Offered Rate (LIBOR) | Credit Facilities | Maximum | Revolving Credit Facility
Debt Instrument [Line Items]
Variable rate margin	1.45%
London Interbank Offered Rate (LIBOR) | Term Loans | $300 Million Term Loan
Debt Instrument [Line Items]
Variable rate margin		1.00%
London Interbank Offered Rate (LIBOR) | Term Loans | $150 Million Term Loan
Debt Instrument [Line Items]
Variable rate margin		1.10%
London Interbank Offered Rate (LIBOR) | Term Loans | Minimum | $300 Million Term Loan
Debt Instrument [Line Items]
Variable rate margin	0.85%
London Interbank Offered Rate (LIBOR) | Term Loans | Maximum | $300 Million Term Loan
Debt Instrument [Line Items]
Variable rate margin	1.65%
Interest Rate Swap | $300 Million Term Loan
Debt Instrument [Line Items]
Notional amount		$ 300,000,000
Interest Rate Swap | $150 Million Term Loan
Debt Instrument [Line Items]
Notional amount		$ 150,000,000

Line of Credit and Notes Paya_4

Line of Credit and Notes Payable (Narrative) (Details)	Dec. 07, 2018USD ($)extension	Oct. 10, 2018USD ($)	May 30, 2018USD ($)	May 29, 2018USD ($)	Apr. 13, 2018USD ($)	Feb. 02, 2018USD ($)	Jun. 30, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Outstanding debt								$ 781,916,000	$ 629,308,000
Carrying value of the line of credit, term loan and notes payable								$ 784,000,000	632,000,000
Weighted-average interest rate								3.55%
Interest payments								$ 17,900,000	22,100,000	$ 21,500,000
Interest capitalized								5,100,000	4,000,000	300,000
(Gain) loss on extinguishment of debt							$ (24,000,000)	0	(23,340,000)	$ 325,000
Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Fair value of line of credit and notes payable								$ 784,100,000	632,100,000
Letter of Credit | Maximum
Debt Instrument [Line Items]
Restrictive covenant ratio of secured debt to total asset								40.00%
Restrictive covenant ratio of debt to total asset								60.00%
Restrictive covenant ratio of debt to total asset following material transaction								65.00%
Credit Facilities | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 500,000,000
Number of possible extensions | extension	2
Term of extension	6 months
Outstanding debt								$ 334,000,000	482,000,000
Credit Facilities | Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 650,000,000
Credit Facilities | Revolving Credit Facility | Base Rate | Minimum
Debt Instrument [Line Items]
Variable rate margin	0.00%
Credit Facilities | Revolving Credit Facility | Base Rate | Maximum
Debt Instrument [Line Items]
Variable rate margin	0.45%
Credit Facilities | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Variable rate margin								0.90%
Credit Facilities | Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Variable rate margin	0.775%
Credit Facilities | Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Variable rate margin	1.45%
Term Loans | $300 Million Term Loan
Debt Instrument [Line Items]
Debt face amount	$ 300,000,000							$ 300,000,000
Outstanding debt								$ 300,000,000	0
Repayments of debt	$ 300,000,000
Term Loans | $300 Million Term Loan | Base Rate | Minimum
Debt Instrument [Line Items]
Variable rate margin	0.00%
Term Loans | $300 Million Term Loan | Base Rate | Maximum
Debt Instrument [Line Items]
Variable rate margin	0.65%
Term Loans | $300 Million Term Loan | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Variable rate margin								1.00%
Term Loans | $300 Million Term Loan | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Variable rate margin	0.85%
Term Loans | $300 Million Term Loan | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Variable rate margin	1.65%
Term Loans | $150 Million Term Loan
Debt Instrument [Line Items]
Debt face amount								$ 150,000,000
Outstanding debt								$ 150,000,000	$ 150,000,000
Term Loans | $150 Million Term Loan | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Variable rate margin								1.10%
Unsecured Debt
Debt Instrument [Line Items]
Fixed charge coverage ratio								1.50
Unencumbered interest coverage ratio, minimum								1.75
Unencumbered leverage ratio, minimum								0.60
Unencumbered leverage ratio following material transaction, minimum								0.65
Line of credit and notes payable
Debt Instrument [Line Items]
Weighted-average interest rate								2.63%	3.26%
Mortgages | One Glenlake Building mortgage note
Debt Instrument [Line Items]
Repayments of debt		$ 20,700,000
Mortgages | 263 Shuman Boulevard Building mortgage note
Debt Instrument [Line Items]
Extinguishment of debt					$ 49,000,000
(Gain) loss on extinguishment of debt							$ (24,000,000)
Bridge Loan | $300 Million Bridge Loan
Debt Instrument [Line Items]
Outstanding debt						$ 300,000,000
Repayments of debt			$ 180,000,000	$ 180,000,000		$ 120,000,000
(Gain) loss on extinguishment of debt			$ 300,000

Line of Credit and Notes Paya_5

Line of Credit and Notes Payable (Maturities) (Details) $ in Thousands	Dec. 31, 2019USD ($)
Debt Disclosure [Abstract]
2020	$ 0
2021	0
2022	150,000
2023	334,000
2024	300,000
Thereafter	0
Total	$ 784,000

Bonds Payable (Details)

Bonds Payable (Details)	12 Months Ended
	Dec. 31, 2019USD ($)bond	Dec. 31, 2018USD ($)bond
Debt Instrument [Line Items]
Number of series of bonds | bond	2	2
Bonds payable, net	$ 698,900,000	$ 698,700,000
Unsecured Debt
Debt Instrument [Line Items]
Number of series of bonds | bond	2	2
Unsecured Debt | 2026 Bonds Payable
Debt Instrument [Line Items]
Debt face amount	$ 350,000,000	$ 350,000,000
Debt term	10 years	10 years
Stated interest rate	3.65%	3.65%
Discount rate of face value of issued debt instrument (percent)	99.626%	99.626%
Unsecured Debt | 2025 Bonds Payable
Debt Instrument [Line Items]
Debt face amount	$ 350,000,000	$ 350,000,000
Debt term	10 years	10 years
Stated interest rate	4.15%	4.15%
Discount rate of face value of issued debt instrument (percent)	99.859%	99.859%
Unsecured Debt | 2018 Bonds Payable
Debt Instrument [Line Items]
Debt face amount	$ 250,000,000
Unsecured Debt | 2026 and 2025 Bonds Payable
Debt Instrument [Line Items]
Interest payments	$ 27,300,000	$ 27,300,000
Restrictive covenant ratio of debt to total asset	60.00%
Restrictive covenant of consolidated income to annual debt service charges	1.50
Fair Value, Inputs, Level 2 | Unsecured Debt | 2026 and 2025 Bonds Payable
Debt Instrument [Line Items]
Estimated fair value of debt instrument	$ 734,400,000	$ 685,000,000
Maximum | Unsecured Debt | 2026 and 2025 Bonds Payable
Debt Instrument [Line Items]
Restrictive covenant ratio of secured debt to total asset	40.00%
Minimum | Unsecured Debt | 2026 and 2025 Bonds Payable
Debt Instrument [Line Items]
Ratio of unencumbered asset value to total unsecured debt	150.00%

Commitments and Contingencies (

Commitments and Contingencies (Lease Obligations) (Details) - USD ($)	Oct. 03, 2018	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Corporate Joint Venture
Loss Contingencies [Line Items]
Capital calls payable				$ 0
Guaranty liability				$ 0
Corporate Joint Venture | 799 Broadway Joint Venture
Loss Contingencies [Line Items]
Proceeds from construction loan	$ 97,000,000		$ 113,200,000
799 Broadway Joint Venture | Corporate Joint Venture
Loss Contingencies [Line Items]
Aggregate additional equity contributions			15,800,000
799 Broadway Joint Venture | Corporate Joint Venture | Normandy And Columbia Property Trust
Loss Contingencies [Line Items]
Aggregate additional equity contributions			31,900,000
149 Madison Avenue
Loss Contingencies [Line Items]
Tenant obligation			17,500,000
95 Columbus
Loss Contingencies [Line Items]
Tenant obligation			$ 17,900,000
80 M Street | Capital Addition Purchase Commitments | Subsequent Event
Loss Contingencies [Line Items]
Required funding amount related to construction and tenant improvement allowances		$ 70,000,000

Stockholders' Equity and Part_3

Stockholders' Equity and Partner's Capital - Narrative (Details) - USD ($)	Jan. 01, 2020	Jan. 01, 2019	Jan. 01, 2018	Jan. 01, 2017	Dec. 31, 2019	Dec. 31, 2017	Dec. 31, 2016	Sep. 04, 2019	Dec. 31, 2018	May 31, 2017	Apr. 30, 2008
Class of Stock [Line Items]
Common stock, par value (in dollars per share)					$ 0.01				$ 0.01
Long Term Incentive Plan
Class of Stock [Line Items]
Shares authorized and reserved under the LTIP										4,800,000
Unrecognized compensation costs related to unvested awards					$ 9,500,000				$ 8,600,000
Time-based Stock Awards | Long Term Incentive Plan
Class of Stock [Line Items]
Granted (shares)		176,122	128,486			139,825
RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Performance period					3 years
Granted (shares)			176,702		256,384	193,219
Performance period						3 years	1 year
Stock Options | Director Stock Option Plan
Class of Stock [Line Items]
Shares authorized and reserved under the LTIP											25,000
Options expired (in shares)				1,375
Options outstanding (in shares)					0
Minimum
Class of Stock [Line Items]
Unrecognized compensation costs recognition period					1 year
Minimum | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Shareholder payout (percent)					50.00%
Maximum
Class of Stock [Line Items]
Unrecognized compensation costs recognition period					4 years
Maximum | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Shareholder payout (percent)					150.00%
36 months after grant date | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Award vesting rights (percent)					75.00%
48 months after grant date | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Stock units exercisable period after the date of grant					1 year
Award vesting rights (percent)					25.00%
Subsequent Event | Time-based Stock Awards | 2020 LTI Plan
Class of Stock [Line Items]
Stock units exercisable period after the date of grant	4 years
Granted (shares)	165,233
Subsequent Event | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Performance period	3 years
Granted (shares)	246,387
Subsequent Event | 36 months after grant date | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Award vesting rights (percent)	75.00%
Subsequent Event | 48 months after grant date | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Stock units exercisable period after the date of grant	1 year
Award vesting rights (percent)	25.00%
Common Stock | Long Term Incentive Plan
Class of Stock [Line Items]
Stock units exercisable period after the date of grant					4 years
Common Stock | 2015 Stock Repurchase Program
Class of Stock [Line Items]
Stock repurchase program, authorized amount								$ 200,000,000
Common stock, par value (in dollars per share)								$ 0.01
Number of shares repurchased (in shares)					1,600,000
Shares repurchased, average cost per share (in dollars per share)					$ 20.72
Value of stock repurchased					$ 33,500,000
Common Stock | Stock Repurchase Program
Class of Stock [Line Items]
Stock repurchase program, amount available for repurchase					$ 166,500,000
2017 Grant 1 | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Performance period						1 year
Granted (shares)						45,076
2017 Grant 2 | RSUs | Long Term Incentive Plan
Class of Stock [Line Items]
Performance period						2 years
Granted (shares)						92,585

Stockholders' Equity and Part_4

Stockholders' Equity and Partner's Capital - Summary of the Activity of the Employee Stock Grants (Details) - Long Term Incentive Plan - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted-Average Grant-Date Fair Value [Abstract]
Expected forfeiture rate	4.00%
Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested shares, beginning balance (shares)	375	389	256
Granted (shares)	176	139	333
Vested (shares)	(165)	(153)	(193)
Forfeited (shares)	(12)	0	(7)
Unvested shares, ending balance (shares)	374	375	389
Weighted-Average Grant-Date Fair Value [Abstract]
Unvested shares, beginning balance (in dollars per share)	$ 22.15	$ 21.85	$ 22.62
Granted (in dollars per share)	19.36	22.97	21.59
Vested (in dollars per share)	21.99	22.13	22.42
Forfeited (in dollars per share)	20.66	0	21.81
Unvested shares, ending balance (in dollars per share)	$ 20.96	$ 22.15	$ 21.85
Shares expected to ultimately vest (in shares)	360
RSUs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested shares, beginning balance (shares)	454	329	0
Granted (shares)	257	206	331
Vested (shares)	(121)	(70)	0
Forfeited (shares)	(6)	(11)	(2)
Unvested shares, ending balance (shares)	584	454	329
Weighted-Average Grant-Date Fair Value [Abstract]
Unvested shares, beginning balance (in dollars per share)	$ 19.37	$ 0	$ 0
Granted (in dollars per share)	17.66	20.55	18.78
Vested (in dollars per share)	19.08	19.47	0
Forfeited (in dollars per share)	18.67	18.60	19.01
Unvested shares, ending balance (in dollars per share)	$ 18.86	$ 19.37	$ 0
Shares expected to ultimately vest (in shares)	562

Stockholders' Equity and Part_5

Stockholders' Equity and Partner's Capital - Summary of Shares Granted to Independent Directors (Details) - Long Term Incentive Plan - Director - $ / shares	May 14, 2019	May 14, 2018	Nov. 27, 2017	May 02, 2017	Jan. 03, 2017
May 14, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares	28,000
Weighted-Average Grant-Date Fair Value (in dollars per share)	$ 22.13
May 14, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares		31,743
Weighted-Average Grant-Date Fair Value (in dollars per share)		$ 22.20
January 3, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares					8,279
Weighted-Average Grant-Date Fair Value (in dollars per share)					$ 21.58
May 2, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares				33,581
Weighted-Average Grant-Date Fair Value (in dollars per share)				$ 22.57
November 27, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares			1,596
Weighted-Average Grant-Date Fair Value (in dollars per share)			$ 23.07

Stockholders' Equity and Part_6

Stockholders' Equity and Partner's Capital - Summary of Incurred Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 6,622	$ 6,966	$ 7,580
Future employee awards	2,720	2,461	2,509
Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,282	3,800	4,098
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 620	$ 705	$ 973

Supplemental Disclosure of No_2

Supplemental Disclosure of Noncash Investing and Financing Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Investment in real estate funded with other assets	$ 0	$ 617	$ 311
Deposits	0	0	10,000
Other assets assumed upon acquisition	6	259	1,014
Other liabilities assumed upon acquisition	137	664	268
Real estate assets transferred to unconsolidated joint venture	0	0	558,122
Other assets transferred to unconsolidated joint venture	0	0	43,700
Other liabilities transferred to unconsolidated joint venture	0	0	21,347
Extinguishment of 263 Shuman Boulevard mortgage note by transferring property to lender	0	49,000	0
Settlement of capital lease obligation with related development authority bonds	0	120,000	0
Amortization of net discounts on debt	180	180	180
Accrued investments in unconsolidated joint ventures	198	386	0
Accrued capital expenditures and deferred lease costs	12,944	15,145	25,069
Operating lease liability recorded at adoption of ASC 842	34,791
Accrued dividends payable	24,209	23,340	23,961
Market value adjustment to interest rate swaps designated as hedging instruments and included in other comprehensive income (loss)	(3,445)	1,441	1,786
Common stock issued to employees and directors, and amortized (net of income tax witholdings)	6,622	6,966	7,580
Non-cash contributions (distributions) from (to) Columbia Property Trust	(7,000)	165,900	(65,200)
Accounting Standards Update 2017-05 And 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment for the adoption of ASU	$ 0	$ 358,098	$ 0

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)ground_lease	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Lessee, Lease, Description [Line Items]
Number of contracts | ground_lease	1
Operating lease assets	$ 29,470
Operating lease liabilities	$ 2,186
Remaining lease term (in years)	7 years 4 months 24 days
Gain (Loss) on Termination of Lease	$ 400	$ 2,200	$ 400
Minimum
Lessee, Lease, Description [Line Items]
Remaining term of contract (in years)	58 years
Maximum
Lessee, Lease, Description [Line Items]
Remaining term of contract (in years)	3 years

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Lease Payments To Be Made (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases [Abstract]
2020	$ 728
2021	760
2022	793
2023	67
2024	0
Thereafter	0
Total lease payments	2,348
Less: interest expense	(162)
Operating lease liabilities	$ 2,186
Weighted-average remaining lease term (years)	3 years 1 month 6 days
Weighted-average discount rate (as a percent)	4.50%

Leases - Summary of Impact of O

Leases - Summary of Impact of Operating Leases on Consolidated Balance Sheet (Details) $ in Thousands	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease assets	$ 29,470
Operating lease liabilities	2,186
Ground Leases
Lessee, Lease, Description [Line Items]
Operating lease assets	27,843
Operating lease liabilities	0
Office Lease
Lessee, Lease, Description [Line Items]
Operating lease assets	1,627
Operating lease liabilities	$ 2,186

Leases - Summary of Impact of_2

Leases - Summary of Impact of Operating Leases on Statements of Operations and Statements of Cash Flows (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease expenses	$ 2,745
Cash paid for operating lease liabilities included in cash flows from operations	(2,026)
Ground Leases
Lessee, Lease, Description [Line Items]
Operating lease expenses	2,165
Cash paid for operating lease liabilities included in cash flows from operations	(1,329)
Office Lease
Lessee, Lease, Description [Line Items]
Operating lease expenses	580
Cash paid for operating lease liabilities included in cash flows from operations	(697)
Property operating costs
Lessee, Lease, Description [Line Items]
Operating lease expenses	2,165
Property operating costs | Ground Leases
Lessee, Lease, Description [Line Items]
Operating lease expenses	2,165
Property operating costs | Office Lease
Lessee, Lease, Description [Line Items]
Operating lease expenses	0
General and administrative – corporate
Lessee, Lease, Description [Line Items]
Operating lease expenses	580
General and administrative – corporate | Ground Leases
Lessee, Lease, Description [Line Items]
Operating lease expenses	0
General and administrative – corporate | Office Lease
Lessee, Lease, Description [Line Items]
Operating lease expenses	$ 580

Leases - Summary of Fixed and V

Leases - Summary of Fixed and Variable Revenues (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Fixed payments	$ 250,077
Variable payments	26,072
Total lease revenues	$ 276,149	$ 276,149	$ 283,252	$ 280,570

Leases - Schedule of Future M_2

Leases - Schedule of Future Minimum Lease Payments To Be Received (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases [Abstract]
2020	$ 223,249
2021	224,999
2022	216,210
2023	205,955
2024	197,846
Thereafter	1,028,119
Total	$ 2,096,378

Non-Lease Revenues (Details)

Non-Lease Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Disaggregation of Revenue [Line Items]
Asset and property management fee income	$ 7.5	$ 7.4	$ 3.8
Lease override fee revenue earned	0.1	0.2
Salary and other reimbursement revenue	4.5	4.4	2.3
Miscellaneous revenue	$ 0.3	$ 0.7	$ 0.6
Difference between Revenue Guidance in Effect before and after Topic 606 | ASU 2014-09
Disaggregation of Revenue [Line Items]
Lease override fees receivable				$ 0.3

Income Taxes (Schedule of Incom

Income Taxes (Schedule of Income Tax Basis Net Income) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
GAAP basis financial statement net income attributable to common stockholders	$ (21,777)	$ (20,286)	$ 47,747	$ 3,513	$ 5,003	$ 6,429	$ (3,439)	$ 1,498	$ 9,197	$ 9,491	$ 176,041
Increase (Decrease) in Net Income Resulting From:
Depreciation and amortization expense for financial reporting purposes in excess of amounts for income tax purposes									41,648	43,753	33,918
Rental income accrued for financial reporting purposes in excess of (less than) amounts for income tax purposes									(10,373)	7,145	(38,426)
Net amortization of above-/below-market lease intangibles for financial reporting purposes less than amounts for income tax purposes									(5,107)	(5,990)	(6,091)
Interest expense for financial reporting purposes in excess of amounts for income tax purposes									5,852		0
Bad debt expense for financial reporting purposes less than (in excess of) amounts for income tax purposes									1	4	(31)
Income from unconsolidated joint ventures for financial reporting purposes in excess of amount for income tax purposes									15,224	16,654	13,902
Gains or losses on disposition of real property for financial reporting purposes that are more favorable than amounts for income tax purposes									(57,284)	79,376	(126,770)
Other expenses or revenues for financial reporting purposes in excess (less than) of amounts for income tax purposes									37,912	(32,342)	11,331
Income tax basis net income, prior to dividends-paid deduction									37,070	$ 118,091	$ 63,874
Tax basis carrying value of total assets	$ 4,400,000								$ 4,400,000

Income Taxes (Distributions) (D

Income Taxes (Distributions) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Ordinary income	53.10%	100.00%	58.50%
Capital gains	0.00%	0.00%	0.00%
Return of capital	46.90%	0.00%	41.50%
Total	100.00%	100.00%	100.00%

Income Taxes (Effective Tax Rat

Income Taxes (Effective Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Total income tax	$ 21	$ 37	$ (213)
Deferred tax asset	200	200
Columbia TRS
Income Tax Contingency [Line Items]
Federal income tax	14	63	188
State income tax	6	(26)	38
Total income tax	$ 20	$ 37	$ 226

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Basic and Diluted EPS Computation) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income	$ (21,777)	$ (20,286)	$ 47,747	$ 3,513	$ 5,003	$ 6,429	$ (3,439)	$ 1,498	$ 9,197	$ 9,491	$ 176,041
Distributions paid on unvested shares									(310)	(296)	(337)
Net income attributable to common stockholders used to calculate basic and diluted earnings per share									$ 8,887	$ 9,195	$ 175,704
Weighted-average common shares – basic									116,261	117,888	120,795
Weighted-average common shares – diluted									116,458	118,311	121,159
Previously granted LTI Plan awards, unvested
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Plus Incremental Weighted-Average Shares from Time-Vested Conversions Less Assumed Share Repurchases:									114	104	116
Future LTI Plan awards
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Plus Incremental Weighted-Average Shares from Time-Vested Conversions Less Assumed Share Repurchases:									83	319	248

Quarterly Results (Unaudited)_2

Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	$ 68,725	$ 71,949	$ 72,730	$ 75,433	$ 75,523	$ 73,340	$ 75,370	$ 73,710	$ 288,837	$ 297,943	$ 289,000
Net income	$ (21,777)	$ (20,286)	$ 47,747	$ 3,513	$ 5,003	$ 6,429	$ (3,439)	$ 1,498	$ 9,197	$ 9,491	$ 176,041
Net income attributable to common stockholders (in dollars per share)	$ (0.19)	$ (0.17)	$ 0.41	$ 0.03	$ 0.04	$ 0.05	$ (0.03)	$ 0.01	$ 0.08	$ 0.08	$ 1.45
Net income attributable to common stockholders (in dollars per share)	(0.19)	(0.17)	0.41	0.03	0.04	0.05	(0.03)	0.01	$ 0.08	$ 0.08	$ 1.45
Dividends declared per share (in dollars per share)	$ 0.21	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20
Gain on sale of real estate			$ 41,900
Impairment loss on real estate		$ 23,400					$ 30,800		$ 43,941	$ 30,812	$ 0
Gain on extinguishment of debt							$ 24,000		$ 0	$ 23,340	$ (325)
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Pasedena Corporate Park
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment loss on real estate	$ 20,600

Segment Information (Operating

Segment Information (Operating Revenues By Geographic Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 31, 2018	Oct. 11, 2017	Jul. 06, 2017	Jul. 05, 2017
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									$ 396,236	$ 403,082	$ 345,955
Operating revenues	$ 68,725	$ 71,949	$ 72,730	$ 75,433	$ 75,523	$ 73,340	$ 75,370	$ 73,710	288,837	297,943	289,000
Asset and property management fee income									7,500	7,400	3,800
Operating Segments
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									393,099	399,917	344,048
Operating Segments | New York
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									157,244	158,077	123,280
Operating Segments | San Francisco
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									114,295	105,947	105,550
Operating Segments | Washington, D.C.
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									58,200	57,274	36,934
Operating Segments | Boston
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									14,285	13,441	11,559
Operating Segments | Los Angeles
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									7,754	7,783	7,462
Operating Segments | All other office markets
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									41,321	57,395	59,263
Segment Reconciling Items
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									0	0	1,328
Asset and property management fee income									7,544	7,384	3,782
Corporate
Segment Reporting Information [Line Items]
Operating revenues including unconsolidated joint venture									3,137	3,165	579
Joint Venture
Segment Reporting Information [Line Items]
Operating revenues									114,943	112,523	60,737
Asset and property management fee income									(7,544)	(7,384)	(3,782)
Corporate Joint Venture
Segment Reporting Information [Line Items]
Asset and property management fee income									$ 7,544	7,384	3,782
114 Fifth Avenue | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	49.50%								49.50%					49.50%
University Circle & 333 Market Street | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	55.00%								55.00%			77.50%			100.00%
Market Square Joint Venture | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	51.00%								51.00%
Asset and property management fee income									$ 2,256	2,156	1,998
1800 M Street Joint Venture | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	55.00%								55.00%				55.00%
Asset and property management fee income									$ 2,156	$ 2,161	$ 417

Segment Information (Reconcilia

Segment Information (Reconciliation of Net Operating Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Oct. 03, 2018	Jan. 31, 2018	Oct. 11, 2017	Jul. 06, 2017	Jul. 05, 2017
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	$ 257,034	$ 271,499	$ 228,875
Operating Segments
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	257,938	272,302	230,614
Operating Segments | New York
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	93,112	94,765	73,893
Operating Segments | San Francisco
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	83,305	79,354	76,163
Operating Segments | Washington, D.C.
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	33,953	34,750	18,496
Operating Segments | Boston
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	7,539	7,205	5,380
Operating Segments | Los Angeles
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	4,601	4,590	4,529
Operating Segments | All other office markets
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	35,428	51,638	52,153
Segment Reconciling Items
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	0	0	(913)
Corporate
Segment Reporting Information [Line Items]
Net operating income including consolidated joint venture	$ (904)	$ (803)	$ (826)
114 Fifth Avenue | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	49.50%						49.50%
799 Broadway Joint Venture | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	49.70%			49.70%
University Circle & 333 Market Street | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	55.00%				77.50%			100.00%
Market Square Joint Venture | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	51.00%
1800 M Street Joint Venture | Corporate Joint Venture
Segment Reporting Information [Line Items]
Ownership percentage	55.00%					55.00%

Segment Information - Reconcili

Segment Information - Reconciliation of Revenue from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net income	$ (21,777)	$ (20,286)	$ 47,747	$ 3,513	$ 5,003	$ 6,429	$ (3,439)	$ 1,498	$ 9,197	$ 9,491	$ 176,041
Depreciation									78,292	81,795	80,394
Amortization									27,908	32,554	32,403
Impairment loss on real estate		$ 23,400					$ 30,800		43,941	30,812	0
General and administrative expense - corporate									32,779	32,979	34,966
General and administrative – joint venture									3,567	3,108	1,454
Pre-acquisition costs (Note 16)									6,398	0	0
Income tax expense									21	37	(213)
Asset and property management fee income									(7,500)	(7,400)	(3,800)
Gain on sale of unconsolidated joint venture interest									0	(762)	0
Gain on sale of real estate assets									(42,030)	0	(175,518)
Adjustment attributable to noncontrolling interests									(133)	0	0
Net operating income									257,034	271,499	228,875
Segment Reconciling Items
Segment Reporting Information [Line Items]
Depreciation									78,292	81,795	80,394
Amortization									27,908	32,554	32,403
Impairment loss on real estate									43,941	30,812	0
General and administrative expense - corporate									32,779	32,979	34,966
General and administrative – joint venture									3,567	3,108	1,454
Pre-acquisition costs (Note 16)									6,398	0	0
Net interest expense									42,997	56,477	58,187
Interest income from development authority bonds									0	(6,871)	(7,200)
(Gain) loss on extinguishment of debt									0	(23,340)	325
Income tax expense									21	37	(213)
Asset and property management fee income									(7,544)	(7,384)	(3,782)
Adjustments included in loss from unconsolidated joint venture									61,634	62,603	31,818
Gain on sale of unconsolidated joint venture interest									0	(762)	0
Gain on sale of real estate assets									(42,030)	0	(175,518)
Adjustment attributable to noncontrolling interests									$ (126)	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details) $ / shares in Units, $ in Millions

Feb. 07, 2020$ / shares

Jan. 24, 2020USD ($)component$ / sharesshares

Jan. 16, 2020USD ($)

Jan. 07, 2020USD ($)

Dec. 31, 2019$ / shares

Sep. 30, 2019$ / shares

Jun. 30, 2019$ / shares

Mar. 31, 2019$ / shares

Dec. 31, 2018$ / shares

Sep. 30, 2018$ / shares

Jun. 30, 2018$ / shares

Mar. 31, 2018$ / shares

Subsequent Event [Line Items]

Dividend declared, per share (in dollars per share) | $ / shares

$ 0.21

$ 0.20

$ 0.20

$ 0.20

$ 0.20

$ 0.20

$ 0.20

$ 0.20

Subsequent Event

Subsequent Event [Line Items]

Dividend declared, per share (in dollars per share) | $ / shares

$ 0.21

Dividends payable

$ 24.2

Subsequent Event | Cranberry Woods Drive

Subsequent Event [Line Items]

Sale of real estate assets

$ 180

Subsequent Event | Normandy Acquisition

Subsequent Event [Line Items]

Purchase price

$ 100

Number of components of purchase price | component

2

Cash payment

$ 13.5

Subsequent Event | Normandy Acquisition | Time-based Stock Awards

Subsequent Event [Line Items]

Issuance of shares (in shares) | shares

128,399

Subsequent Event | Normandy Acquisition | Performance-Based Restricted Stock Units

Subsequent Event [Line Items]

Issuance of shares (in shares) | shares

104,968

Subsequent Event | Normandy Acquisition | Columbia OP

Subsequent Event [Line Items]

Ownership percentage

97.20%

Subsequent Event | Normandy Acquisition | Series A Convertible, Perpetual Preferred Units

Subsequent Event [Line Items]

Issuance of shares (in shares) | shares

3,264,151

Liquidation preference (usd per share) | $ / shares

$ 26.50

Schedule III - Real Estate As_2

Schedule III - Real Estate Assets and Accumulated Depreciation and Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Real Estate and Accumulated Depreciation [Line Items]
Gross Amount at Which Carried at December 31, 2019, Total	$ 3,336,448	$ 3,345,301	$ 3,612,294	$ 4,243,531
Aggregate cost of land and buildings and improvements for federal income tax purposes	$ 3,475,000
Building Improvements | Minimum
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	5 years
Building Improvements | Maximum
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	25 years
Office Lease | Minimum
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties
Real Estate and Accumulated Depreciation [Line Items]
Initial Costs, Land	$ 937,754
Initial Costs, Building and Improvements	2,234,203
Initial Costs, Total	3,171,957
Costs Capitalized Subsequent to Acquisition	164,491
Gross Amount at Which Carried at December 31, 2019, Land	927,468
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	2,408,980
Gross Amount at Which Carried at December 31, 2019, Total	3,336,448
Accumulated Depreciation and Amortization	$ 418,979
Consolidated Properties | 80 M Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	26,248
Initial Costs, Building and Improvements	76,269
Initial Costs, Total	102,517
Costs Capitalized Subsequent to Acquisition	6,732
Gross Amount at Which Carried at December 31, 2019, Land	26,806
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	82,443
Gross Amount at Which Carried at December 31, 2019, Total	109,249
Accumulated Depreciation and Amortization	$ 29,214
Consolidated Properties | 95 Columbus
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	29,061
Initial Costs, Building and Improvements	141,544
Initial Costs, Total	170,605
Costs Capitalized Subsequent to Acquisition	13,137
Gross Amount at Which Carried at December 31, 2019, Land	29,712
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	154,030
Gross Amount at Which Carried at December 31, 2019, Total	183,742
Accumulated Depreciation and Amortization	$ 72,086
Consolidated Properties | Pasadena Corporate Park
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	53,099
Initial Costs, Building and Improvements	59,630
Initial Costs, Total	112,729
Costs Capitalized Subsequent to Acquisition	(20,992)
Gross Amount at Which Carried at December 31, 2019, Land	41,604
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	50,133
Gross Amount at Which Carried at December 31, 2019, Total	91,737
Accumulated Depreciation and Amortization	$ 22,463
Consolidated Properties | Cranberry Woods Drive
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	15,512
Initial Costs, Building and Improvements	173,062
Initial Costs, Total	188,574
Costs Capitalized Subsequent to Acquisition	15,187
Gross Amount at Which Carried at December 31, 2019, Land	15,512
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	188,249
Gross Amount at Which Carried at December 31, 2019, Total	203,761
Accumulated Depreciation and Amortization	$ 58,079
Consolidated Properties | 221 Main Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	60,509
Initial Costs, Building and Improvements	174,629
Initial Costs, Total	235,138
Costs Capitalized Subsequent to Acquisition	19,871
Gross Amount at Which Carried at December 31, 2019, Land	60,509
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	194,500
Gross Amount at Which Carried at December 31, 2019, Total	255,009
Accumulated Depreciation and Amortization	$ 41,491
Consolidated Properties | 650 California Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	75,384
Initial Costs, Building and Improvements	240,441
Initial Costs, Total	315,825
Costs Capitalized Subsequent to Acquisition	27,757
Gross Amount at Which Carried at December 31, 2019, Land	75,384
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	268,198
Gross Amount at Which Carried at December 31, 2019, Total	343,582
Accumulated Depreciation and Amortization	$ 49,732
Consolidated Properties | 315 Park Avenue South
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	119,633
Initial Costs, Building and Improvements	249,510
Initial Costs, Total	369,143
Costs Capitalized Subsequent to Acquisition	35,718
Gross Amount at Which Carried at December 31, 2019, Land	119,633
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	285,228
Gross Amount at Which Carried at December 31, 2019, Total	404,861
Accumulated Depreciation and Amortization	$ 38,039
Consolidated Properties | 116 Huntington Avenue
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	0
Initial Costs, Building and Improvements	116,290
Initial Costs, Total	116,290
Costs Capitalized Subsequent to Acquisition	26,670
Gross Amount at Which Carried at December 31, 2019, Land	0
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	142,960
Gross Amount at Which Carried at December 31, 2019, Total	142,960
Accumulated Depreciation and Amortization	$ 25,824
Consolidated Properties | 229 West 43rd Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	207,233
Initial Costs, Building and Improvements	292,991
Initial Costs, Total	500,224
Costs Capitalized Subsequent to Acquisition	2,226
Gross Amount at Which Carried at December 31, 2019, Land	207,233
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	295,217
Gross Amount at Which Carried at December 31, 2019, Total	502,450
Accumulated Depreciation and Amortization	$ 47,597
Consolidated Properties | 249 West 17th Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	113,149
Initial Costs, Building and Improvements	221,517
Initial Costs, Total	334,666
Costs Capitalized Subsequent to Acquisition	4,354
Gross Amount at Which Carried at December 31, 2019, Land	113,149
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	225,871
Gross Amount at Which Carried at December 31, 2019, Total	339,020
Accumulated Depreciation and Amortization	$ 18,867
Consolidated Properties | 218 West 18th Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	43,836
Initial Costs, Building and Improvements	139,077
Initial Costs, Total	182,913
Costs Capitalized Subsequent to Acquisition	5,716
Gross Amount at Which Carried at December 31, 2019, Land	43,836
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	144,793
Gross Amount at Which Carried at December 31, 2019, Total	188,629
Accumulated Depreciation and Amortization	$ 14,868
Consolidated Properties | 149 Madison Avenue
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	59,112
Initial Costs, Building and Improvements	28,989
Initial Costs, Total	88,101
Costs Capitalized Subsequent to Acquisition	22,408
Gross Amount at Which Carried at December 31, 2019, Land	59,112
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	51,397
Gross Amount at Which Carried at December 31, 2019, Total	110,509
Accumulated Depreciation and Amortization	$ 0
Consolidated Properties | 101 Franklin Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	92.50%
Encumbrances	$ 0
Initial Costs, Land	57,145
Initial Costs, Building and Improvements	149,500
Initial Costs, Total	206,645
Costs Capitalized Subsequent to Acquisition	2,373
Gross Amount at Which Carried at December 31, 2019, Land	57,145
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	151,873
Gross Amount at Which Carried at December 31, 2019, Total	209,018
Accumulated Depreciation and Amortization	$ 0
Consolidated Properties | 201 California Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	100.00%
Encumbrances	$ 0
Initial Costs, Land	77,833
Initial Costs, Building and Improvements	170,754
Initial Costs, Total	248,587
Costs Capitalized Subsequent to Acquisition	3,334
Gross Amount at Which Carried at December 31, 2019, Land	77,833
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	174,088
Gross Amount at Which Carried at December 31, 2019, Total	251,921
Accumulated Depreciation and Amortization	$ 719
Consolidated Properties | Minimum | 80 M Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 95 Columbus
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | Pasadena Corporate Park
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | Cranberry Woods Drive
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 221 Main Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 650 California Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 315 Park Avenue South
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 116 Huntington Avenue
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 229 West 43rd Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 249 West 17th Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 218 West 18th Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 149 Madison Avenue
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 101 Franklin Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Minimum | 201 California Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Consolidated Properties | Maximum | 80 M Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 95 Columbus
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | Pasadena Corporate Park
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | Cranberry Woods Drive
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 221 Main Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 650 California Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 315 Park Avenue South
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 116 Huntington Avenue
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 229 West 43rd Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 249 West 17th Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 218 West 18th Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 149 Madison Avenue
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 101 Franklin Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Consolidated Properties | Maximum | 201 California Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Unconsolidated Properties
Real Estate and Accumulated Depreciation [Line Items]
Initial Costs, Land	$ 566,331
Initial Costs, Building and Improvements	1,682,797
Initial Costs, Total	2,249,128
Costs Capitalized Subsequent to Acquisition	(69,136)
Gross Amount at Which Carried at December 31, 2019, Land	566,594
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	1,613,398
Gross Amount at Which Carried at December 31, 2019, Total	2,179,992
Accumulated Depreciation and Amortization	179,073
Initial cost of land, buildings and improvements net of encumbrances	$ 1,834,000
Unconsolidated Properties | Market Square
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	51.00%
Encumbrances	$ 325,000
Initial Costs, Land	152,629
Initial Costs, Building and Improvements	450,757
Initial Costs, Total	603,386
Costs Capitalized Subsequent to Acquisition	(15,552)
Gross Amount at Which Carried at December 31, 2019, Land	152,629
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	435,205
Gross Amount at Which Carried at December 31, 2019, Total	587,834
Accumulated Depreciation and Amortization	$ 59,629
Unconsolidated Properties | University Circle
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	55.00%
Encumbrances	$ 0
Initial Costs, Land	27,493
Initial Costs, Building and Improvements	278,288
Initial Costs, Total	305,781
Costs Capitalized Subsequent to Acquisition	(96,941)
Gross Amount at Which Carried at December 31, 2019, Land	27,756
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	181,084
Gross Amount at Which Carried at December 31, 2019, Total	208,840
Accumulated Depreciation and Amortization	$ 13,591
Unconsolidated Properties | 333 Market Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	55.00%
Encumbrances	$ 0
Initial Costs, Land	114,483
Initial Costs, Building and Improvements	292,840
Initial Costs, Total	407,323
Costs Capitalized Subsequent to Acquisition	(41,230)
Gross Amount at Which Carried at December 31, 2019, Land	114,483
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	251,610
Gross Amount at Which Carried at December 31, 2019, Total	366,093
Accumulated Depreciation and Amortization	$ 20,680
Unconsolidated Properties | 114 Fifth Avenue
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	49.50%
Encumbrances	$ 0
Initial Costs, Land	0
Initial Costs, Building and Improvements	383,694
Initial Costs, Total	383,694
Costs Capitalized Subsequent to Acquisition	2,301
Gross Amount at Which Carried at December 31, 2019, Land	0
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	385,995
Gross Amount at Which Carried at December 31, 2019, Total	385,995
Accumulated Depreciation and Amortization	$ 52,714
Unconsolidated Properties | 1800 M Street
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	55.00%
Encumbrances	$ 0
Initial Costs, Land	125,735
Initial Costs, Building and Improvements	272,353
Initial Costs, Total	398,088
Costs Capitalized Subsequent to Acquisition	35,285
Gross Amount at Which Carried at December 31, 2019, Land	125,735
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	307,638
Gross Amount at Which Carried at December 31, 2019, Total	433,373
Accumulated Depreciation and Amortization	$ 32,459
Unconsolidated Properties | 799 Broadway
Real Estate and Accumulated Depreciation [Line Items]
Ownership percentage	49.70%
Encumbrances	$ 113,200
Initial Costs, Land	145,991
Initial Costs, Building and Improvements	4,865
Initial Costs, Total	150,856
Costs Capitalized Subsequent to Acquisition	47,001
Gross Amount at Which Carried at December 31, 2019, Land	145,991
Gross Amount at Which Carried at December 31, 2019, Buildings and Improvements	51,866
Gross Amount at Which Carried at December 31, 2019, Total	197,857
Accumulated Depreciation and Amortization	$ 0
Unconsolidated Properties | Minimum | Market Square
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Unconsolidated Properties | Minimum | University Circle
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Unconsolidated Properties | Minimum | 333 Market Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Unconsolidated Properties | Minimum | 114 Fifth Avenue
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Unconsolidated Properties | Minimum | 1800 M Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Unconsolidated Properties | Minimum | 799 Broadway
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	0 years
Unconsolidated Properties | Maximum | Market Square
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Unconsolidated Properties | Maximum | University Circle
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Unconsolidated Properties | Maximum | 333 Market Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Unconsolidated Properties | Maximum | 114 Fifth Avenue
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Unconsolidated Properties | Maximum | 1800 M Street
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Unconsolidated Properties | Maximum | 799 Broadway
Real Estate and Accumulated Depreciation [Line Items]
Real estate and accumulated depreciation, life used for depreciation	40 years
Corporate | Consolidated Properties
Real Estate and Accumulated Depreciation [Line Items]
Gross Amount at Which Carried at December 31, 2019, Total	$ 3,200

Schedule III - Real Estate As_3

Schedule III - Real Estate Assets and Accumulated Depreciation and Amortization (Rollforward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 31, 2018	Jul. 05, 2017
Real Estate:
Balance at beginning of year	$ 3,345,301	$ 3,612,294	$ 4,243,531
Additions to/improvements of real estate	531,336	87,398	698,567
Sale/transfer of real estate	(456,331)	(313,683)	(1,285,915)
Impairment of real estate	(43,941)	(30,812)	0
Write-offs of building and tenant improvements	(270)	(1,464)	(3,087)
Write-offs of intangible assets	(34,039)	(6,131)	(14,432)
Write-offs of fully depreciated assets	(5,608)	(2,301)	(26,370)
Balance at end of year	3,336,448	3,345,301	3,612,294
Accumulated Depreciation and Amortization:
Balance at beginning of year	487,485	482,627	729,025
Depreciation and amortization expense	90,926	98,858	97,732
Sale/transfer of real estate	(149,708)	(84,965)	(302,157)
Write-offs of tenant improvements	(228)	(603)	(1,406)
Write-offs of intangible assets	(3,888)	(6,131)	(14,197)
Write-offs of fully depreciated assets	(5,608)	(2,301)	(26,370)
Balance at end of year	$ 418,979	$ 487,485	$ 482,627
University Circle & 333 Market Street | Corporate Joint Venture
Accumulated Depreciation and Amortization:
Percentage of real estate transferred	100.00%
Ownership percentage	55.00%			77.50%	100.00%

Uncategorized Items - cxp-20191

Label	Element	Value
Accounting Standards Update 2017-05 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 357,755,000
Accounting Standards Update 2017-05 [Member] | Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	357,755,000
Accounting Standards Update 2017-05 [Member] | Accumulated Distributions in Excess of Net Income [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	357,755,000
Accounting Standards Update 2014-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	343,000
Accounting Standards Update 2014-09 [Member] | Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	343,000
Accounting Standards Update 2014-09 [Member] | Accumulated Distributions in Excess of Net Income [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 343,000