Equity Commonwealth (EQC) 10-K28 Feb 142013 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2013	Feb. 24, 2014	Jun. 28, 2013
Document and Entity Information	'	'	'
Entity Registrant Name	'CommonWealth REIT	'	'
Entity Central Index Key	'0000803649	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Amendment Flag	'false	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Public Float	'	'	$2.70
Entity Common Stock, Shares Outstanding	'	118,403,105	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Real estate properties:	'	'
Land	$699,135	$1,531,416
Buildings and improvements	4,838,030	6,297,993
Total real estate properties, at cost, gross	5,537,165	7,829,409
Accumulated depreciation	-895,059	-1,007,606
Total real estate properties, at cost, net	4,642,106	6,821,803
Properties held for sale	573,531	171,832
Acquired real estate leases, net	255,812	427,756
Equity investments	517,991	184,711
Cash and cash equivalents	222,449	102,219
Restricted cash	22,101	16,626
Rents receivable, net of allowance for doubtful accounts of $7,885 and $9,962, respectively	223,769	253,394
Other assets, net	188,675	211,293
Total assets	6,646,434	8,189,634
LIABILITIES AND SHAREHOLDERS' EQUITY	'	'
Revolving credit facility	235,000	297,000
SIR revolving credit facility	'	95,000
Senior unsecured debt, net	1,855,900	2,972,994
Mortgage notes payable, net	914,510	984,827
Liabilities related to properties held for sale	28,734	2,339
Accounts payable and accrued expenses	165,855	194,184
Assumed real estate lease obligations, net	33,935	69,304
Rent collected in advance	27,553	35,700
Security deposits	11,976	23,860
Due to related persons	9,385	12,958
Total liabilities	3,282,848	4,688,166
Commitments and contingencies	'	'
Common shares of beneficial interest, $0.01 par value:	'	'
Common shares of beneficial interest, $0.01 par value: 350,000,000 shares authorized; 118,386,918 and 83,804,068 shares issued and outstanding, respectively	1,184	838
Additional paid in capital	4,213,474	3,585,400
Cumulative net income	2,209,840	2,386,900
Cumulative other comprehensive (loss) income	-38,331	565
Cumulative common distributions	-3,082,271	-2,972,569
Cumulative preferred distributions	-573,971	-529,367
Total shareholder's equity attributable to CommonWealth REIT	3,363,586	3,105,428
Noncontrolling interest in consolidated subsidiary	'	396,040
Total shareholders' equity	3,363,586	3,501,468
Total liabilities and shareholders' equity	6,646,434	8,189,634
Series D	'	'
50,000,000 shares authorized;	'	'
Preferred shares of beneficial interest, $0.01 par value	368,270	368,270
Series E	'	'
50,000,000 shares authorized;	'	'
Preferred shares of beneficial interest, $0.01 par value	$265,391	$265,391

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Rents receivable, allowance for doubtful accounts (in dollars)	$7,885	$9,962
Common shares of beneficial interest, par value (in dollars per share)	$0.01	$0.01
Common shares of beneficial interest, shares authorized	350,000,000	350,000,000
Common shares of beneficial interest, shares issued	118,386,918	83,804,068
Common shares of beneficial interest, shares outstanding	118,386,918	83,804,068
Series D	'	'
Preferred shares of beneficial interest, par value (in dollars per share)	$0.01	$0.01
Preferred shares of beneficial interest, shares authorized	50,000,000	50,000,000
Preferred shares, dividend yield (as a percent)	6.50%	6.50%
Preferred shares of beneficial interest, shares issued	15,180,000	15,180,000
Preferred shares of beneficial interest, shares outstanding	15,180,000	15,180,000
Preferred shares, aggregate liquidation preference (in dollars)	379,500	379,500
Series E	'	'
Preferred shares of beneficial interest, par value (in dollars per share)	$0.01	$0.01
Preferred shares of beneficial interest, shares authorized	50,000,000	50,000,000
Preferred shares, dividend yield (as a percent)	7.25%	7.25%
Preferred shares of beneficial interest, shares issued	11,000,000	11,000,000
Preferred shares of beneficial interest, shares outstanding	11,000,000	11,000,000
Preferred shares, aggregate liquidation preference (in dollars)	$275,000	$275,000

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:	'	'	'
Rental income	$707,380	$709,390	$601,632
Tenant reimbursements and other income	178,156	172,515	139,712
Total revenues	885,536	881,905	741,344
Expenses:	'	'	'
Operating expenses	370,869	356,604	297,408
Depreciation and amortization	218,854	209,759	171,662
General and administrative	77,209	46,057	38,221
Loss on asset impairment	'	'	3,036
Acquisition related costs	318	5,648	9,731
Total expenses	667,250	618,068	520,058
Operating income	218,286	263,837	221,286
Interest and other income	1,229	1,404	1,662
Interest expense (including net amortization of debt discounts, premiums and deferred financing fees of $9, $3,296 and $6,751, respectively)	-173,011	-201,840	-191,876
Loss on early extinguishment of debt	-60,052	-287	-35
Gain on sale of equity investment	66,293	'	'
Gain on issuance of shares by an equity investee	'	7,246	11,177
Income from continuing operations before income tax expense and equity in earnings of investees	52,745	70,360	42,214
Income tax expense	-2,634	-3,207	-1,347
Equity in earnings of investees	25,754	11,420	11,377
Income from continuing operations	75,865	78,573	52,244
Discontinued operations:	'	'	'
Income from discontinued operations	15,867	9,783	22,307
Loss on asset impairment from discontinued operations	-227,122	-168,632	-7,319
Loss on early extinguishment of debt from discontinued operations	-1,011	-1,608	'
Net (loss) gain on sale of properties from discontinued operations	-22,162	2,039	42,752
(Loss) income before gain on sale of properties	-158,563	-79,845	109,984
Gain on sale of properties	1,596	'	'
Net (loss) income	-156,967	-79,845	109,984
Net income attributable to noncontrolling interest in consolidated subsidiary	-20,093	-15,576	'
Net (loss) income attributable to CommonWealth REIT	-177,060	-95,421	109,984
Preferred distributions	-44,604	-51,552	-46,985
Excess redemption price paid over carrying value of preferred shares	'	-4,985	'
Net (loss) income	-221,664	-151,958	62,999
Amounts attributable to CommonWealth REIT common shareholders:	'	'	'
Income from continuing operations	12,764	6,460	5,259
Income from discontinued operations	15,867	9,783	22,307
Loss on asset impairment from discontinued operations	-227,122	-168,632	-7,319
Loss on early extinguishment of debt from discontinued operations	-1,011	-1,608	'
Net (loss) gain on sale of properties from discontinued operations	-22,162	2,039	42,752
Net (loss) income	($221,664)	($151,958)	$62,999
Weighted average common shares outstanding - basic and diluted (in shares)	112,378	83,750	77,428
Basic and diluted earnings per common share attributable to CommonWealth REIT common shareholders:	'	'	'
Income from continuing operations (in dollars per share)	$0.11	$0.08	$0.07
(Loss) income from discontinued operations (in dollars per share)	($2.09)	($1.89)	$0.75
Net (loss) income (in dollars per share)	($1.97)	($1.81)	$0.81

CONSOLIDATED_STATEMENTS_OF_OPE1

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED STATEMENTS OF OPERATIONS	'	'	'
Amortization of debt discounts, premiums and deferred financing fees	$9	$3,296	$6,751

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME	'	'	'
Net (loss) income	($156,967)	($79,845)	$109,984
Other comprehensive income (loss), net of tax:	'	'	'
Unrealized gain (loss) on derivative instruments	4,918	-828	-8,840
Realized gain on sale of investment in available for sale securities	'	'	-19
Foreign currency translation adjustments	-43,718	6,062	-632
Equity in unrealized (loss) income of an investee	-132	47	76
Total comprehensive (loss) income	-195,899	-74,564	100,569
Less: comprehensive income attributable to noncontrolling interest in consolidated subsidiary	-20,057	-15,583	'
Comprehensive (loss) income attributable to CommonWealth REIT	($215,956)	($90,147)	$100,569

CONSOLIDATED_STATEMENTS_OF_SHA

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $)	Total	Preferred Shares	Preferred Shares	Preferred Shares	Cumulative Preferred Distributions	Common Shares	Cumulative Common Distributions	Additional Paid in Capital	Cumulative Net Income	Cumulative Other Comprehensive Income (Loss)	Noncontrolling Interest in Consolidated Subsidiary
In Thousands, except Share data, unless otherwise specified	Total	Series C	Series D	Series E	Cumulative Preferred Distributions	Common Shares	Cumulative Common Distributions	Additional Paid in Capital	Cumulative Net Income	Cumulative Other Comprehensive Income (Loss)	Noncontrolling Interest in Consolidated Subsidiary
Balance at Dec. 31, 2010	$3,131,690	$145,015	$368,270	'	($432,252)	$721	($2,675,956)	$3,348,849	$2,372,337	$4,706	'
Balance (in shares) at Dec. 31, 2010	'	6,000,000	15,180,000	'	'	72,138,686	'	'	'	'	'
Comprehensive income (loss):	'	'	'	'	'	'	'	'	'	'	'
Net (loss) income	109,984	'	'	'	'	'	'	'	109,984	'	'
Unrealized gain (loss) on derivative instruments	-8,840	'	'	'	'	'	'	'	'	-8,840	'
Realized gain on sale of investment in available for sale securities	-19	'	'	'	'	'	'	'	'	-19	'
Foreign currency translation adjustments	-632	'	'	'	'	'	'	'	'	-632	'
Equity in unrealized income (loss) of an investee	76	'	'	'	'	'	'	'	'	76	'
Total comprehensive (loss) income	100,569	'	'	'	'	'	'	'	'	'	'
Issuance of shares, net	529,698	'	'	265,391	'	115	'	264,192	'	'	'
Issuance of shares, net (in shares)	'	'	'	11,000,000	'	11,500,000	'	'	'	'	'
Share grants	1,039	'	'	'	'	1	'	1,038	'	'	'
Share grants (in shares)	'	'	'	'	'	83,050	'	'	'	'	'
Distributions	-194,479	'	'	'	-44,405	'	-150,074	'	'	'	'
Balance at Dec. 31, 2011	3,568,517	145,015	368,270	265,391	-476,657	837	-2,826,030	3,614,079	2,482,321	-4,709	'
Balance (in shares) at Dec. 31, 2011	'	6,000,000	15,180,000	11,000,000	'	83,721,736	'	'	'	'	'
Comprehensive income (loss):	'	'	'	'	'	'	'	'	'	'	'
Net (loss) income	-79,845	'	'	'	'	'	'	'	-95,421	'	15,576
Unrealized gain (loss) on derivative instruments	-828	'	'	'	'	'	'	'	'	-828	'
Foreign currency translation adjustments	6,062	'	'	'	'	'	'	'	'	6,062	'
Equity in unrealized income (loss) of an investee	47	'	'	'	'	'	'	'	'	40	7
Total comprehensive (loss) income	-74,564	'	'	'	'	'	'	'	'	'	'
Issuance of shares of subsidiary, net	363,657	'	'	'	'	'	'	'	'	'	363,657
Redemption of shares	-150,000	-145,015	'	'	'	'	'	-4,985	'	'	'
Redemption of shares (in shares)	'	-6,000,000	'	'	'	'	'	'	'	'	'
Share grants	1,493	'	'	'	'	1	'	1,123	'	'	369
Share grants (in shares)	'	'	'	'	'	82,332	'	'	'	'	'
Adjustments to noncontrolling interest resulting from changes in ownership of a subsidiary	'	'	'	'	'	'	'	-24,817	'	'	24,817
Distributions	-207,635	'	'	'	-52,710	'	-146,539	'	'	'	-8,386
Balance at Dec. 31, 2012	3,501,468	'	368,270	265,391	-529,367	838	-2,972,569	3,585,400	2,386,900	565	396,040
Balance (in shares) at Dec. 31, 2012	83,804,068	'	15,180,000	11,000,000	'	83,804,068	'	'	'	'	'
Comprehensive income (loss):	'	'	'	'	'	'	'	'	'	'	'
Net (loss) income	-156,967	'	'	'	'	'	'	'	-177,060	'	20,093
Unrealized gain (loss) on derivative instruments	4,918	'	'	'	'	'	'	'	'	4,918	'
Foreign currency translation adjustments	-43,718	'	'	'	'	'	'	'	'	-43,718	'
Equity in unrealized income (loss) of an investee	-132	'	'	'	'	'	'	'	'	-96	-36
Total comprehensive (loss) income	-195,899	'	'	'	'	'	'	'	'	'	'
Issuance of shares, net	626,809	'	'	'	'	345	'	626,506	'	'	-42
Issuance of shares, net (in shares)	'	'	'	'	'	34,500,000	'	'	'	'	'
Share grants	1,821	'	'	'	'	1	'	1,536	'	'	284
Share grants (in shares)	'	'	'	'	'	82,850	'	'	'	'	'
Adjustments to noncontrolling interest resulting from changes in ownership of a subsidiary	'	'	'	'	'	'	'	32	'	'	-32
Distributions	-169,169	'	'	'	-44,604	'	-109,702	'	'	'	-14,863
Deconsolidation of a subsidiary	-401,444	'	'	'	'	'	'	'	'	'	-401,444
Balance at Dec. 31, 2013	$3,363,586	'	$368,270	$265,391	($573,971)	$1,184	($3,082,271)	$4,213,474	$2,209,840	($38,331)	'
Balance (in shares) at Dec. 31, 2013	118,386,918	'	15,180,000	11,000,000	'	118,386,918	'	'	'	'	'

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'	'
Net (loss) income	($156,967)	($79,845)	$109,984
Adjustments to reconcile net (loss) income to cash provided by operating activities:	'	'	'
Depreciation	178,353	188,123	166,444
Net amortization of debt discounts, premiums and deferred financing fees	81	3,405	6,943
Straight line rental income	-31,229	-38,812	-31,474
Amortization of acquired real estate leases	59,274	60,176	48,441
Other amortization	18,850	19,955	16,744
Loss on asset impairment	227,122	168,632	10,355
Loss on early extinguishment of debt	61,063	1,895	35
Equity in earnings of investees	-25,754	-11,420	-11,377
Gain on issuance of shares by an equity investee	'	-7,246	-11,177
Gain on sale of equity investment	-66,293	'	'
Distributions of earnings from investees	23,911	10,835	11,238
Net loss (gain) on sale of properties	20,566	-2,039	-42,752
Change in assets and liabilities:	'	'	'
Restricted cash	-1,832	-6,216	-2,787
Rents receivable and other assets	-57,039	-38,801	-31,362
Accounts payable and accrued expenses	-14,333	6,034	12,589
Rent collected in advance	125	-1,104	8,479
Security deposits	611	1,548	1,933
Due to related persons	-1,858	1,663	1,076
Cash provided by operating activities	234,651	276,783	263,332
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'	'
Real estate acquisitions	-154,370	-631,279	-768,060
Real estate improvements	-114,451	-131,300	-100,339
Investment in direct financing lease, net	'	'	-38,635
Principal payments received from direct financing lease	6,970	6,645	5,256
Principal payments received from real estate mortgages receivable	1,000	'	8,183
Proceeds from sale of properties, net	224,976	9,643	264,284
Proceeds from sale of equity investment, net	239,576	'	'
Distributions in excess of earnings from investees	168	5,981	5,379
Investment in Affiliates Insurance Company	'	-5,335	'
Increase in restricted cash	-3,685	-2,541	'
Deconsolidation of a subsidiary	-12,286	'	'
Cash provided by (used in) investing activities	187,898	-748,186	-623,932
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'	'
Proceeds from issuance of common shares, net	626,809	363,657	264,056
Proceeds from issuance of preferred shares, net	'	'	265,391
Redemption of preferred shares	'	-150,000	'
Repurchase and retirement of outstanding debt securities	-728,021	'	'
Proceeds from borrowings	1,036,000	1,702,500	1,007,000
Payments on borrowings	-1,065,432	-1,312,982	-975,030
Deferred financing fees	-1,204	-15,117	-7,131
Distributions to common shareholders	-109,702	-146,539	-150,074
Distributions to preferred shareholders	-44,604	-52,710	-44,405
Distributions to noncontrolling interest in consolidated subsidiary	-14,863	-8,386	'
Cash (used in) provided by financing activities	-301,017	380,423	359,807
Effect of exchange rate changes on cash	-1,302	436	-484
Increase (decrease) in cash and cash equivalents	120,230	-90,544	-1,277
Cash and cash equivalents at beginning of year	102,219	192,763	194,040
Cash and cash equivalents at end of year	222,449	102,219	192,763
SUPPLEMENTAL CASH FLOW INFORMATION:	'	'	'
Interest paid	192,010	204,772	186,774
Taxes paid	1,303	779	966
NON-CASH INVESTING ACTIVITIES:	'	'	'
Real estate acquisitions	'	-370,139	-321,235
Investment in real estate mortgages receivable	-7,688	-1,419	'
Net assets transferred to Select Income REIT	492,736	'	'
NON-CASH FINANCING ACTIVITIES:	'	'	'
Issuance of common shares	1,537	1,124	1,039
Assumption of mortgage notes payable	'	359,213	321,235
Liabilities assumed	'	10,926	'
Assumption of note payable	'	'	$4,059

Organization

Organization	12 Months Ended
Organization	Dec. 31, 2013
Organization	'
Organization	'

	Note 1. Organization

	CommonWealth REIT is a real estate investment trust, or REIT, formed in 1986 under the laws of the State of Maryland. Our primary business is the ownership and operation of real estate, primarily office buildings located throughout the United States. At December 31, 2013, our portfolio included 125 properties (195 buildings) with a combined 37,273,000 square feet (excluding properties classified as held for sale), which consisted of: (i) 38 properties (51 buildings) with a combined 20,975,000 square feet located in central business district, or CBD, locations, and (ii) 87 properties (144 buildings) with a combined 16,298,000 square feet located in suburban locations. Eleven of our properties (11 buildings) with a combined 1,759,000 square feet are located in Australia.

	As of December 31, 2013, we also owned 22,000,000 common shares, or approximately 44.2% of the outstanding common shares, of Select Income REIT. We refer to Select Income REIT and its consolidated subsidiaries as SIR. SIR is a REIT that primarily owns and invests in net leased, single tenant office and industrial properties throughout the United States and leased lands in Hawaii and was a 100% owned subsidiary of ours until March 12, 2012, on which date SIR completed an initial public offering of 9,200,000 of its common shares, or the SIR IPO, and became a publicly owned company with shares listed on the New York Stock Exchange, or the NYSE. On July 2, 2013, SIR issued and sold to the public 10,500,000 of its common shares. Prior to the completion of this offering, our 22,000,000 common shares of SIR represented approximately 56.0% of SIR's outstanding common shares, and SIR was one of our consolidated subsidiaries. Following the completion of this offering, our 22,000,000 common shares of SIR represented approximately 44.2% of SIR's outstanding common shares, and SIR ceased to be our consolidated subsidiary. Because our investment in SIR was reduced below 50%, effective July 2, 2013, we no longer consolidate our investment in SIR but instead account for such investment under the equity method. See Notes 6 and 12 for additional information regarding SIR.

	Until March 15, 2013, we also owned 9,950,000, or approximately 18.2%, of the common shares of Government Properties Income Trust, or GOV. GOV, a REIT that primarily owns properties located throughout the United States that are majority leased to government tenants, was our wholly owned subsidiary until its initial public offering in June 2009, when it became a publicly owned company with shares listed on the NYSE. See Notes 6 and 12 for additional information regarding GOV.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2013
Summary of Significant Accounting Policies	'
Summary of Significant Accounting Policies	'

	Note 2. Summary of Significant Accounting Policies

	Basis of Presentation. The consolidated financial statements include our investments in 100% owned subsidiaries and majority owned subsidiaries that are controlled by us. References to we, us, our and the Company, refer to CommonWealth REIT and its consolidated subsidiaries as of December 31, 2013, unless the context indicates otherwise. The portion of a consolidated subsidiary that is not controlled by us, or the noncontrolling interest, is presented as a separate component of equity in our consolidated balance sheets. In addition, net income attributable to the noncontrolling interest is presented separately in our consolidated statements of operations. All intercompany transactions and balances have been eliminated.

	We account for our investments in 50% or less owned companies, including our investments in SIR (beginning on July 2, 2013 when SIR ceased to be our consolidated subsidiary), GOV (until March 15, 2013, when we sold all of our GOV common shares) and Affiliates Insurance Company, or AIC, over which we can exercise influence, but do not control, using the equity method of accounting. Significant influence is present through common representation on the boards of trustees or directors of us and each of SIR, GOV and AIC. Our two Managing Trustees are also managing trustees of SIR and GOV, and owners of Reit Management & Research LLC, or RMR, which is the business and property manager of us, SIR, GOV and AIC, and a majority of our Trustees are directors of AIC. We use the income statement method to account for issuance of common shares of beneficial interest by SIR and GOV (until March 15, 2013, when we sold all of our GOV common shares), and shares of common stock by AIC. Under this method, gains and losses reflecting changes in the value of our investments at the date of issuance of additional common shares by SIR and GOV, or common stock by AIC, are recognized in our income statement.

	Real Estate Properties. We record real estate properties at cost. We depreciate real estate investments on a straight line basis over estimated useful lives of up to 40 years for buildings and improvements, and up to 12 years for personal property.

	We allocate the consideration paid for our properties among land, buildings and improvements and, for properties that qualify as acquired businesses under the Business Combinations Topic of the FASB Accounting Standards Codification^TM, or the Codification, to identified intangible assets and liabilities, consisting of the value of above market and below market leases, the value of acquired in place leases and the value of tenant relationships. Purchase price allocations and the determination of useful lives are based on our estimates and, under some circumstances, studies from independent real estate appraisal firms to provide market information and evaluations that are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determination of useful lives.

	We allocate the consideration to land, buildings and improvements based on a determination of the fair values of these assets assuming the property is vacant. We determine the fair value of a property using methods that we believe are similar to those used by independent appraisers. Purchase price allocations to above market and below market leases are based on the estimated present value (using an interest rate which reflects our assessment of the risks associated with the leases acquired) of the difference between (1) the contractual amounts to be paid pursuant to the acquired in place leases and (2) our estimate of fair market lease rates for the corresponding leases, measured over a period equal to the remaining non-cancelable terms of the respective leases. Purchase price allocations to acquired in place leases and tenant relationships are determined as the excess of (1) the purchase price paid for a property after adjusting existing in place leases to estimated market rental rates over (2) the estimated fair value of the property as if vacant. We aggregate this value between acquired in place lease values and tenant relationships based on our evaluation of the specific characteristics of each tenant's lease; however, the value of tenant relationships has not been separated from acquired in place lease value for our properties because we believe such value and related amortization expense is immaterial for acquisitions reflected in our historical financial statements. We consider certain factors in performing these analyses including estimates of carrying costs during the expected lease up periods, including real estate taxes, insurance and other operating income and expenses and costs to execute similar leases in current market conditions, such as leasing commissions, legal and other related costs. If we believe the value of tenant relationships is material in the future, those amounts will be separately allocated and amortized over the estimated lives of the relationships. We recognize the excess, if any, of the consideration paid over amounts allocated to land, buildings and improvements and identified intangible assets and liabilities as goodwill and we recognize gains if amounts allocated exceed the consideration paid.

	We amortize capitalized above market lease values (presented in our consolidated balance sheets as acquired real estate leases) as a reduction to rental income over the remaining terms of the respective leases. We amortize capitalized below market lease values (presented in our consolidated balance sheets as assumed real estate lease obligations) as an increase to rental income over the remaining terms of the respective leases. Such amortization resulted in net reductions to rental income of $10,158, $10,274 and $8,766 during the years ended December 31, 2013, 2012 and 2011, respectively, and net increases to income from discontinued operations of $623, $312 and $286, for the years ended December 31, 2013, 2012 and 2011, respectively. We amortize the value of acquired in place leases exclusive of the value of above market and below market acquired in place leases to expense over the remaining terms of the respective leases. The amount of such amortization included in depreciation and amortization totaled $47,586, $45,475 and $32,907 during the years ended December 31, 2013, 2012 and 2011, respectively. The amount of such amortization included in income from discontinued operations totaled $2,157, $4,740 and $7,058 during the years ended December 31, 2013, 2012 and 2011, respectively. If a lease is terminated prior to its stated expiration, the unamortized amount relating to that lease is written off.

	Capitalized above market lease values for properties held and used in operations were $127,944 and $190,402 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $48,841 and $56,374, respectively, as of those same respective dates. Capitalized above market lease values for properties held for sale was $2,047 and $1,191 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $0 and $1,060, respectively, as of those same respective dates. Capitalized below market lease values for properties held and used in operations were $56,815 and $106,643 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $22,880 and $37,339, respectively, as of those same respective dates. Capitalized below market lease values for properties held for sale was $4,996 and $92 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $2,926 and $71, respectively, as of those same respective dates. The value of acquired in place leases, exclusive of the value of above and below market in place leases for properties held and used in operations were $282,754 and $393,068 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $106,045 and $99,340, respectively, as of those same respective dates. The value of acquired in place leases, exclusive of the value of above and below market in place leases for properties held for sale was $9,351 and $2,297 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $4,461 and $1,975, respectively, as of those same respective dates. Future amortization of net intangible lease assets and liabilities to be recognized by us during the current terms of our leases as of December 31, 2013 are approximately $46,204 in 2014, $39,690 in 2015, $32,172 in 2016, $24,996 in 2017, $20,876 in 2018 and $57,939 thereafter.

	We recognize impairment losses on investments when indicators of impairment are present and the estimated undiscounted cash flow from our investments is less than the carrying amount of such investments. Impairment indicators may include declining tenant occupancy, lack of progress releasing vacant space, tenant bankruptcies, low long term prospects for improvement in property performance, weak or declining tenant profitability, cash flow or liquidity, our decision to dispose of an asset before the end of its estimated useful life and legislative, market or industry changes that could permanently reduce the value of a property. We review our properties for impairment quarterly, or whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable. If indicators of impairment are present, we evaluate the carrying value of the related property by comparing it to the expected future undiscounted cash flows to be generated from that property. If the sum of these expected future cash flows is less than the carrying value, we reduce the net carrying value of the property to its estimated fair value. The determination of undiscounted cash flow includes consideration of many factors including income to be earned from the investment, holding costs (exclusive of interest), estimated selling prices, and prevailing economic and market conditions.

	When we classify properties as held for sale, we discontinue the recording of depreciation expense and estimate their fair value less costs to sell. If we determine that the carrying value for these properties exceed their estimated fair value less costs to sell, we record a loss on asset impairment. During the year ended December 31, 2013, we recorded a loss on asset impairment totaling $204,036 to reduce the carrying value of 39 properties (93 buildings) classified as held for sale to their estimated fair value less costs to sell (see Note 14). In addition, we recorded losses on asset impairment for properties sold during 2013 totaling $23,086.

	Certain of our real estate assets contain hazardous substances, including asbestos. We believe any asbestos in our buildings is contained in accordance with current regulations, and we have no current plans to remove any such asbestos. If we remove the asbestos or renovate or demolish these properties, certain environmental regulations govern the manner in which the asbestos must be handled and removed. We do not believe that there are other environmental conditions at any of our properties that have a material adverse effect on us. However, no assurances can be given that such conditions are not present in our properties or that other costs we incur to remediate contamination will not have a material adverse effect on our business or financial condition. As of December 31, 2013 and 2012, accrued environmental remediation costs by us and SIR (as of December 31, 2012 only, when SIR was our consolidated subsidiary) totaling $418 and $10,798, respectively, were included in accounts payable and accrued expenses in our consolidated balance sheets.

	Cash and Cash Equivalents. We carry cash and short term investments with original maturities of three months or less at the date of purchase at cost plus accrued interest.

	Restricted Cash. Restricted cash consists of amounts escrowed for future real estate taxes, insurance, leasing costs, capital expenditures and debt service, as required by some of our mortgage debts, as well as security deposits paid to us by some of our tenants.

	Other Assets, Net. Other assets consist principally of deferred financing fees, deferred leasing costs, capitalized lease incentives and prepaid property operating expenses. Deferred financing fees include issuance costs related to borrowings and are capitalized and amortized over the terms of the respective loans. At December 31, 2013 and 2012, deferred financing fees totaled $45,985 and $58,783, respectively, and accumulated amortization for deferred financing fees totaled $21,455 and $21,623, respectively, as of those same respective dates. At December 31, 2013, deferred financing fees for properties held for sale totaled $272, and accumulated amortization for deferred financing fees for properties held for sale totaled $132, as of that same respective date. Deferred leasing costs include brokerage, legal and other fees associated with the successful negotiation of leases and are amortized on a straight line basis over the terms of the respective leases. Deferred leasing costs for properties held and used in operations totaled $146,996 and $151,115 at December 31, 2013 and 2012, respectively, and accumulated amortization for deferred leasing costs for properties held and used in operations totaled $46,228 and $49,652, respectively, as of those same respective dates. Deferred leasing costs for properties held for sale totaled $13,769 and $4,771 at December 31, 2013 and 2012, respectively, and accumulated amortization for deferred leasing costs for properties held for sale totaled $987 and $2,110, respectively, as of those same respective dates. Capitalized lease incentives are amortized on a straight line basis against rental income over the terms of the respective leases. Capitalized lease incentives for properties held and used in operations totaled $20,651 and $20,491 at December 31, 2013 and 2012, respectively, and accumulated amortization for capitalized lease incentives for properties held and used in operations totaled $5,392 and $3,828, respectively, as of those same respective dates. Capitalized lease incentives for properties held for sale totaled $590 as of December 31, 2013, and accumulated amortization for capitalized lease incentives for properties held for sale totaled $40, as of that same respective date. Future amortization of deferred financing fees and leasing costs to be recognized by us during the current terms of our loans and leases as of December 31, 2013 are approximately $22,693 in 2014, $21,041 in 2015, $17,274 in 2016, $14,233 in 2017, $12,230 in 2018 and $37,827 thereafter. Future amortization of capitalized lease incentives to be recognized by us during the current terms of our leases as of December 31, 2013 are approximately $2,256 in 2014, $2,236 in 2015, $2,225 in 2016, $2,152 in 2017, $2,069 in 2018 and $4,321 thereafter.

	Accounting Policy for Derivative Instruments. The Derivatives and Hedging Topic of the Codification requires companies to recognize all their derivative instruments as either assets or liabilities in the statement of financial position at fair value. The accounting for changes in the fair value of a derivative instrument depends on whether such instrument has been designated and qualifies as part of a hedging relationship and, further, on the type of hedging relationship. For those derivative instruments that are designated and qualify as hedging instruments, we must designate the hedging instrument, based upon the exposure being hedged, as a fair value hedge, cash flow hedge or a hedge of a net investment in a foreign operation. In December 2009, we entered into interest rate swap agreements that qualify as cash flow hedges. As of December 31, 2013 and 2012, the fair value of our derivative instrument of $11,706 and $16,624, respectively, was included in accounts payable and accrued expenses and cumulative other comprehensive (loss) income in our consolidated balance sheets.

	We are exposed to certain risks relating to our ongoing business operations. The primary risk managed by using derivative instruments is interest rate risk. Interest rate swaps are entered into to manage interest rate risk associated with our floating rate borrowings. We designate certain interest rate swaps as cash flow hedges of floating rate borrowings.

	Revenue Recognition. Rental income from operating leases, which includes rent concessions (including free rent and other lease incentives) and scheduled increases in rental rates during the lease term, is recognized on a straight line basis over the life of the lease agreements. We defer the recognition of contingent rental income, such as percentage rents, until the specific targets that trigger the contingent rental income are achieved. Tenant reimbursements and other income includes property level operating expenses reimbursed by our tenants, as well as other incidental revenues.

	Allowance for Doubtful Accounts. We maintain an allowance for doubtful accounts for estimated losses resulting from the inability or unwillingness of certain tenants to make payments required under their leases. The computation of the allowance is based on the tenants' payment histories and current credit profiles, as well as other considerations.

	Earnings Per Common Share. Earnings per common share, or EPS, is computed using the weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if our series D convertible preferred shares were converted into our common shares, where such conversion would result in a lower EPS amount. The effect of our series D convertible preferred shares on income from continuing operations and net income available for common shareholders is anti-dilutive for all periods presented.

	As discussed in Note 3, if the consent solicitation by Related Fund Management, LLC and Corvex Management LP, or together, Related/Corvex, is successful in removing our entire Board of Trustees, such removal would constitute a fundamental change under our 6.5% series D cumulative convertible preferred shares giving holders of such shares the option to convert these shares into common shares at a ratio based on 98% of the average closing market price for a period before such removal is effective unless we repurchase these shares for their par value plus accrued and unpaid distributions. The issuance of such a large number of common shares as a result of the exercise of this conversion right after a fundamental change may have a dilutive effect on income from continuing operations attributable to CommonWealth REIT common shareholders per share for future periods.

	Reclassifications. Reclassifications have been made to the prior years' financial statements and notes to conform to the current year's presentation.

	Income Taxes. We are a REIT under the Internal Revenue Code of 1986, as amended, and are generally not subject to federal and state income taxes provided we distribute our taxable income to our shareholders and meet other requirements for qualifying as a real estate investment trust. However, we are subject to certain state, local and Australian taxes without regard to our REIT status.

	The Income Taxes Topic of the Codification prescribes how we should recognize, measure and present in our financial statements uncertain tax positions that have been taken or are expected to be taken in a tax return. Deferred tax assets are recognized to the extent that it is "more likely than not" that a particular tax position will be sustained upon examination or audit. To the extent the "more likely than not" standard has been satisfied, the benefit associated with a tax position is measured as the largest amount that has a greater than 50% likelihood of being realized upon settlement. We classify interest and penalties related to uncertain tax positions, if any, in our financial statements as a component of general and administrative expense.

	Use of Estimates. Preparation of these financial statements in conformity with U.S. generally accepted accounting principles, or GAAP, requires us to make estimates and assumptions that may affect the amounts reported in these financial statements and related notes. The actual results could differ from these estimates.

	Foreign Operations. The U.S. dollar is the functional currency for our consolidated subsidiaries operating in the United States. The functional currency for our consolidated subsidiaries in countries other than the United States is the principal currency in which the entity's assets, liabilities, income and expenses are denominated. The functional currency of our consolidated subsidiary that operates in Australia is the Australian dollar. We translate our Australian subsidiary's financial statements into U.S. dollars when we consolidate that subsidiary's financial statements on a quarterly basis. Generally, we translate assets and liabilities at the exchange rate in effect as of the balance sheet date. The resulting translation adjustments are included in cumulative other comprehensive (loss) income in our consolidated balance sheets. We translate income statement accounts using the average exchange rate for the period and income statement accounts that include significant non-recurring transactions at the rate in effect as of the date of the transaction. We are subject to foreign currency risk due to potential fluctuations in exchange rates between Australian and U.S. currencies. A significant change in the value of Australian currency compared to U.S. currency would have an effect on future reported results of operations and financial position. We do not currently borrow in Australian dollars or enter currency derivative contracts to mitigate foreign currency risk. As of December 31, 2013 and 2012, cumulative foreign currency translation adjustments were ($26,647) and $17,071, respectively.

	New Accounting Pronouncements. Effective January 2013, we adopted Financial Accounting Standards Board, or FASB, Accounting Standards Update No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This update is the culmination of the FASB's deliberation on reporting reclassification adjustments from accumulated other comprehensive income, or AOCI. This standard does not change the current requirements for reporting net income or other comprehensive income. However, it requires disclosure of amounts reclassified out of AOCI in their entirety, by component, on the face of the statement of operations or in the notes thereto. Amounts that are not required to be reclassified in their entirety to net income must be cross referenced to other disclosures that provide additional detail. This update was effective prospectively for interim and annual reporting periods beginning after December 15, 2012. The implementation of this update did not cause any material changes to the presentation of our consolidated financial statements.

Board_of_Trustees

Board of Trustees	12 Months Ended
Board of Trustees	Dec. 31, 2013
Board of Trustees	'
Board of Trustees	'

	Note 3. Board of Trustees

	Since Related/Corvex publicly announced on February 26, 2013 that they had accumulated common shares of the Company, they have undertaken a series of actions in an effort to influence and control us, including publishing "open" letters to our Board of Trustees, announcing conditional, unfinanced purported offers to acquire all the Company's common shares, running a consent solicitation seeking to remove, without cause, all of the members of our Board of Trustees which the arbitration panel formed to hear the disputes between the Company and Related/Corvex, or the Arbitration Panel, determined "was not properly conducted and cannot be validated" and pursing legal proceedings against the Company, the Board of Trustees and RMR. The Arbitration Panel also provided for a limited opportunity for Related/Corvex to conduct a new consent solicitation within a limited time period. Related/Corvex have filed a definitive solicitation statement with the Securities and Exchange Commission for (i) a new consent solicitation for their proposal to remove, without cause, all of the members of our Board of Trustees, including the two recently added Independent Trustees, and (ii) in the event this removal proposal is successful, the solicitation of proxies for the election of seven nominees for new trustees proposed by Related/Corvex at a special meeting of shareholders which would be required for the election of replacement trustees. We have filed a definitive consent revocation statement in opposition to the Related/Corvex removal proposal. Our Board of Trustees has set a record date of February 18, 2014 for purposes of determining shareholders entitled to execute or revoke consents to the Related/Corvex removal proposal and, under the rules established by the Arbitration Panel, the Related/Corvex consent solicitation must be concluded within 30 days of the record date, or March 20, 2014. The Arbitration Panel also ruled that, in the event the Related/Corvex consent solicitation succeeds in removing all of our Trustees, our officers must promptly call a special meeting of shareholders for the election of successor trustees, and that only shareholders who have held 1%, or $2,000 in market value, of our common shares continuously for one year may submit nominations for successor trustees to be elected at that special meeting.

	If our entire Board of Trustees is removed as a result of the Related/Corvex consent solicitation, that action may, among other things, disrupt our business and operations and affect our ability to pay dividends, repurchase shares, borrow money and implement our business plan, and have other effects which may adversely affect us.

Real_Estate_Properties

Real Estate Properties	12 Months Ended
Real Estate Properties	Dec. 31, 2013
Real Estate Properties	'
Real Estate Properties	'

	Note 4. Real Estate Properties

	The information presented in this Note 4 excludes information related to SIR and its consolidated subsidiaries, unless the context indicates otherwise.

	We did not make any acquisitions during the year ended December 31, 2013.

	During the year ended December 31, 2013, we made improvements totaling $122,927 to our properties, including improvements made by SIR to its properties for the period that SIR was our consolidated subsidiary until July 2, 2013.

	Property Sales:

	During the year ended December 31, 2013, we sold 43 properties (134 buildings) with a combined 8,343,955 square feet and two land parcels for an aggregate sale price of $249,132, excluding closing costs and other adjustments. Details of these completed sales are as follows:

	Sales of properties resulting in gains and losses:



	•
	In January 2013, we sold three suburban office and industrial properties (18 buildings) with a combined 1,060,026 square feet for an aggregate sale price of $10,250, excluding closing costs. In connection with the sale of these properties, we provided mortgage financing to the buyer, an unrelated third party, totaling $7,688 at 6.0% per annum and recognized a gain on sale of $1,277.

	•
	As a result of an eminent domain taking in March 2013, we sold a land parcel adjacent to one of our CBD properties for $1,806, excluding closing costs, and recognized a gain on sale of $1,596.

	•
	In June 2013, we sold a suburban property (one building) with 30,105 square feet for $1,600, excluding closing costs, and recognized a gain on sale of $317.



	•
	Also in June 2013, we sold a parcel of land for $2,551, excluding closing costs, and recognized a gain on sale of $1,765.

	•
	In December 2013, we sold three suburban properties (40 buildings) with a combined 1,670,104 square feet for an aggregate sale price of $89,000, excluding closing costs and other adjustments, and recognized a loss of $25,521.

	Sales of properties with previously recorded asset impairment losses:



	•
	In April 2013, we sold a suburban property (one building) with 618,000 square feet for $830, excluding closing costs.

	•
	In May 2013, we sold a suburban property (one building) with 57,250 square feet for $4,025, excluding closing costs.

	•
	In June 2013, we sold a suburban property (two buildings) with a combined 356,045 square feet for an aggregate sale price of $16,300, excluding closing costs.

	•
	Also in June 2013, we sold a suburban property (one building) with 143,802 square feet for $5,250, excluding closing costs.

	•
	In August 2013, we sold a suburban property (three buildings) with a combined 129,452 square feet for an aggregate sale price of $4,100, excluding closing costs.

	•
	In October 2013, we sold nine suburban properties (41 buildings) with a combined 1,211,536 square feet for an aggregate sale price of $43,000, excluding closing costs.

	•
	Also in October 2013, we sold a suburban property (one building) with 665,545 square feet for $13,900, excluding closing costs.

	•
	Also in October 2013, we sold a suburban property (two buildings) with a combined 199,418 square feet for an aggregate sale price of $4,000, excluding closing costs.

	•
In November 2013, we sold 18 CBD and suburban properties (21 buildings) with a combined 2,125,278 square feet for an aggregate sale price of $50,500, excluding closing costs.

•
In December 2013, we sold two suburban properties (two buildings) with a combined 77,394 square feet for an aggregate sale price of $2,020, excluding closing costs.

We classify all properties that meet the criteria outlined in the Property, Plant and Equipment Topic of the FASB Accounting Standards Codification^TM, or the Codification, as held for sale, as such on our consolidated balance sheets. As of December 31, 2012, we had one CBD property (one building) and 39 suburban properties (93 buildings) with a combined 6,673,851 square feet held for sale. As of December 31, 2013, we had three CBD properties (four buildings) and 42 suburban properties (106 buildings) with a combined 8,425,548 square feet held for sale. We expect to sell these properties during 2014; however, no assurance can be given that these properties will be sold in that time period or at all, or what the ultimate terms of those sales may be. Results of operations for properties sold or held for sale are included in discontinued operations in our consolidated statements of operations once the criteria for discontinued operations in the Presentation of Financial Statements Topic of the Codification are met. Summarized balance sheet information for all properties classified as held for sale and income statement information for properties held for sale or sold is as follows:

Balance Sheets:


		December 31,
		2013			2012
Real estate properties		$	536,552		$	164,041
Acquired real estate leases			6,937			453
Rents receivable			14,180			2,791
Other assets, net			15,862			4,547


Properties held for sale		$	573,531		$	171,832




Mortgage notes payable, net		$	20,018		$	—
Assumed real estate lease obligations			2,070			21
Rent collected in advance			4,043			854
Security deposits			2,603			1,464


Liabilities related to properties held for sale		$	28,734		$	2,339





Income Statements:


		Year Ended December 31,
		2013			2012			2011
Rental income		$	110,955		$	134,962		$	163,159
Tenant reimbursements and other income			18,453			22,128			27,905


Total revenues			129,408			157,090			191,064


Operating expenses			76,203			87,774			104,449
Depreciation and amortization			28,098			48,533			51,493
General and administrative			7,563			8,675			9,254
Acquisition related costs			—			—			471


Total expenses			111,864			144,982			165,667


Operating income			17,544			12,108			25,397
Interest and other income			65			79			58
Interest expense			(1,742	)		(2,404	)		(3,148	)


Income from discontinued operations		$	15,867		$	9,783		$	22,307





Our real estate properties are generally leased on gross lease, modified gross lease or triple net lease bases pursuant to non-cancelable, fixed term operating leases expiring between 2014 and 2032. Our triple net leases generally require the lessee to pay all property operating costs. Our gross leases and modified gross leases require us to pay all or some property operating expenses and to provide all or some property management services.

We committed $128,486 for expenditures related to 5,152,000 square feet of leases executed during 2013. Committed but unspent tenant related obligations based on existing leases as of December 31, 2013, were $89,986.

The future minimum lease payments scheduled to be received by us during the current terms of our leases as of December 31, 2013 are as follows:


2014		$	589,603
2015			564,468
2016			501,714
2017			441,682
2018			391,015
Thereafter			1,350,719


		$	3,839,201





One of our real estate properties is subject to a ground lease. The land on this property is leased pursuant to a non-cancelable, fixed term operating ground lease that expires in 2098.

The future minimum lease payments scheduled to be paid by us during the current terms of this ground lease under which we are the lessee, as of December 31, 2013, are as follows:


2014		$	1,477
2015			1,477
2016			1,477
2017			1,477
2018			1,483
Thereafter			131,496


		$	138,887





The amount of ground lease expense included in operating expenses during the years ended December 31, 2013, 2012 and 2011, totaled $1,857, $1,828 and $1,850, respectively.

Investment_in_Direct_Financing

Investment in Direct Financing Lease	12 Months Ended
Investment in Direct Financing Lease	Dec. 31, 2013
Investment in Direct Financing Lease	'
Investment in Direct Financing Lease	'

	Note 5. Investment in Direct Financing Lease

	We have an investment in a direct financing lease that relates to a lease with a term that exceeds 75% of the useful life of an office tower located within a mixed use property in Phoenix, AZ. We recognize income using the effective interest method to produce a level yield on funds not yet recovered. Estimated unguaranteed residual values at the date of lease inception represent our initial estimates of the fair value of the leased assets at the expiration of the lease, which do not exceed their original cost. Significant assumptions used in estimating residual values include estimated net cash flows over the remaining lease term and expected future real estate values. The carrying amount of our net investment is included in other assets in our consolidated balance sheets. The following table summarizes the carrying amount of our net investment in this direct financing lease:


		December 31,
		2013			2012
	Total minimum lease payments receivable	$	22,986		$	31,084
	Estimated unguaranteed residual value of leased asset		4,951			4,951
	Unearned income		(8,174	)		(9,302	)


	Net investment in direct financing lease	$	19,763		$	26,733





	We monitor the payment history and credit profile of the tenant and have determined that no allowance for losses related to our direct financing lease was necessary at December 31, 2013 and 2012.

	Our direct financing lease has an expiration date in 2045. Future minimum rentals receivable on this direct financing lease as of December 31, 2013 are as follows:


	2014	$	8,098
	2015		8,098
	2016		226
	2017		226
	2018		226
	Thereafter		6,112


		$	22,986

Equity_Investments

Equity Investments	12 Months Ended
Equity Investments	Dec. 31, 2013
Equity Investments	'
Equity Investments	'

	Note 6. Equity Investments

	At December 31, 2013 and 2012, we had the following equity investments in SIR, GOV and AIC:


			Ownership Percentage						Equity Investments				Equity in Earnings
			December 31,						December 31,				Year Ended December 31,
			2013			2012			2013		2012		2013		2012		2011
	SIR			44.2	%		56.00%	-1	$	512,078	$	—	$	21,153	$	—	$	—
	GOV			0	%		18.20%			—		173,452		4,111		10,836		11,238
	AIC			12.5	%		25.00%			5,913		11,259		490		584		139


									$	517,991	$	184,711	$	25,754	$	11,420	$	11,377






	-1
	SIR's financial position and results of operations were consolidated in our financial statements as of December 31, 2012, and therefore not reflected in the table above.

	At December 31, 2013, we owned 22,000,000, or approximately 44.2%, of the common shares of beneficial interest of SIR, with a carrying value of $512,078 and a market value, based on quoted market prices, of $588,280 ($26.74 per share). SIR is a REIT that is primarily focused on owning and investing in net leased, single tenant properties and was one of our consolidated subsidiaries until July 2, 2013. On July 2, 2013, SIR issued and sold to the public 10,500,000 of its common shares for $28.25 per common share. Prior to the completion of this offering, our 22,000,000 common shares of SIR represented approximately 56.0% of SIR's outstanding common shares, and SIR was one of our consolidated subsidiaries. Following the completion of this offering, our 22,000,000 common shares of SIR represented approximately 44.2% of SIR's outstanding common shares and SIR ceased to be our consolidated subsidiary. Accordingly, since the completion of this offering on July 2, 2013, we no longer consolidate our investment in SIR, but instead account for this investment under the equity method. Under the equity method, we record our percentage share of net earnings of SIR in our consolidated statements of operations. Prior to July 2, 2013, the operating results and investments of SIR were included in our consolidated results of operations and financial position. On July 2, 2013, our share of the underlying equity of SIR exceeded our carrying value by $17,609. As required under GAAP, we are amortizing this difference to equity in earnings of investees over a 34 year period, which approximates the average remaining useful lives of the buildings owned by SIR as of July 2, 2013. If we determine there is an "other than temporary" decline in the fair value of this investment, we would record a charge to earnings. See Notes 1 and 12 for additional information regarding SIR.

	Since July 2, 2013, we have received cash distributions from SIR totaling $19,800.

	The following summarized financial data of SIR as reported in SIR's Annual Report on Form 10-K for the year ended December 31, 2013, or the SIR Annual Report, includes the financial position and results of operations for periods prior to July 2, 2013 (the date SIR ceased to be our consolidated subsidiary), which are included in our consolidated results of operations when SIR was our consolidated subsidiary. References in our financial statements to the SIR Annual Report are included as references to the source of the data only, and the information in the SIR Annual Report is not incorporated by reference into our financial statements.

	Consolidated Balance Sheets:


			December 31,
			2013			2012
	Real estate properties, net		$	1,579,234		$	1,249,081
	Acquired real estate leases, net			129,426			95,248
	Cash and cash equivalents			20,025			20,373
	Rents receivable, net			55,335			38,885
	Other assets, net			17,839			27,065


	Total assets		$	1,801,859		$	1,430,652




	Revolving credit facility		$	159,000		$	95,000
	Term loan			350,000			350,000
	Mortgage notes payable			27,147			27,778
	Assumed real estate lease obligations, net			26,966			20,434
	Other liabilities			40,055			37,257
	Shareholders' equity			1,198,691			900,183


	Total liabilities and shareholders' equity		$	1,801,859		$	1,430,652





	Consolidated Statements of Income:


		Year Ended December 31,
		2013			2012			2011
Rental income		$	159,011		$	105,559		$	91,775
Tenant reimbursements and other income			29,312			17,231			16,847


Total revenues			188,323			122,790			108,622


Operating expenses			36,382			23,796			22,946
Depreciation and amortization			31,091			14,860			11,205
Acquisition related costs			2,002			2,470			—
General and administrative			12,423			8,203			5,528


Total expenses			81,898			49,329			39,679


Operating income			106,425			73,461			68,943
Interest expense			(13,763	)		(7,565	)		—


Income before income tax expense and equity in earnings of an investee			92,662			65,896			68,943
Income tax benefit (expense)			96			(290	)		—
Equity in earnings of an investee			334			269			—


Net income		$	93,092		$	65,875		$	68,943




Weighted average common shares outstanding			44,565			27,122			—




Net income per common share		$	2.09		$	2.43			N/A





On March 15, 2013, we sold all 9,950,000 common shares that we owned of GOV in a public offering for $25.20 per common share, raising gross proceeds of $250,740 ($239,576 after deducting underwriters' discounts and commissions and expenses). We recognized a gain on this sale of an equity investment of $66,293 as a result of the per share sales price of this transaction being above our per share carrying value. GOV is a REIT which primarily owns properties that are majority leased to government tenants and was our wholly owned subsidiary until its initial public offering in June 2009 when it became a separate public entity.

During the years ended December 31, 2013, 2012 and 2011, we received cash distributions from GOV totaling $4,279, $16,816 and $16,617, respectively.

The following summarized financial data of GOV as of December 31, 2012 and for the two years then ended, is as reported in GOV's Annual Report on Form 10-K for the year ended December 31, 2013, or the GOV Annual Report. References in our financial statements to the GOV Annual Report are included as references to the source of the data only, and the information in the GOV Annual Report is not incorporated by reference into our financial statements.

Consolidated Balance Sheets:


		December 31,
		2012
Real estate properties, net		$	1,311,202
Assets of discontinued operations			47,142
Acquired real estate leases, net			144,402
Cash and cash equivalents			5,255
Rents receivable, net			28,882
Other assets, net			25,251


Total assets		$	1,562,134




Unsecured revolving credit facility		$	49,500
Unsecured term loan			350,000
Mortgage notes payable			93,127
Liabilities of discontinued operations			298
Assumed real estate lease obligations, net			19,129
Other liabilities			22,629
Shareholders' equity			1,027,451


Total liabilities and shareholders' equity		$	1,562,134





Consolidated Statements of Income:


		Year Ended
		December 31,
		2012			2011
Rental income		$	203,700		$	168,074


Operating expenses			75,326			62,117
Depreciation and amortization			49,070			37,776
Acquisition related costs			1,614			3,504
General and administrative			11,924			10,469


Total expenses			137,934			113,866


Operating income			65,766			54,208
Interest and other income			29			104
Interest expense			(16,892	)		(12,057	)


Income from continuing operations before income tax expense and equity in earnings of an investee			48,903			42,255
Income tax expense			(159	)		(203	)
Equity in earnings of an investee			316			139


Income from continuing operations			49,060			42,191
Income from discontinued operations			900			3,806


Net income		$	49,960		$	45,997




Weighted average common shares outstanding			48,617			43,368




Per common share:
Income from continuing operations		$	1.01		$	0.97




Income from discontinued operations		$	0.02		$	0.09




Net income		$	1.03		$	1.06





As of December 31, 2013, we have invested $5,209 in AIC, an insurance company owned in equal proportion by us, RMR, GOV, SIR and four other companies to which RMR provides management services. At December 31, 2013, we owned 12.5% of AIC with a carrying value of $5,913. For the period that SIR was both a shareholder of AIC and our consolidated subsidiary, from May 2012 until July 2, 2013, our consolidated financial statements include SIR's equity investment interest in AIC. We and SIR use the equity method to account for our and SIR's investment in AIC because we and SIR believe that we each have significant influence over AIC because a majority of our Trustees and all of SIR's trustees are also directors of AIC. Following our deconsolidation of SIR, we continue to account for our investment in AIC under the equity method, as we continue to believe we have significant influence over AIC for the same reason. Under the equity method, we record our and our percentage share of SIR's percentage share of net earnings from AIC in our consolidated statements of operations. If we determine there is an "other than temporary" decline in the fair value of this investment, we would record a charge to earnings. In evaluating the fair value of this investment, we have considered, among other things, the assets and liabilities held by AIC, AIC's overall financial condition and the financial condition and prospects for AIC's insurance business. See Note 12 for additional information about our investment in AIC.

Real_Estate_Mortgages_Receivab

Real Estate Mortgages Receivable	12 Months Ended
Real Estate Mortgages Receivable	Dec. 31, 2013
Real Estate Mortgages Receivable	'
Real Estate Mortgages Receivable	'

	Note 7. Real Estate Mortgages Receivable

	We provided mortgage financing totaling $7,688 at 6.0% per annum in connection with our sale of three suburban office and industrial properties (18 buildings) in January 2013. This real estate mortgage requires monthly interest payments and matures on January 24, 2023. We also provided mortgage financing totaling $419 at 6.0% per annum in connection with our sale of a suburban office property in Salina, NY in April 2012. This real estate mortgage requires monthly interest payments and matures on April 30, 2019. In addition, in September 2013, another buyer of a property we sold prepaid to us in full a $1,000 real estate mortgage that was scheduled to mature on July 1, 2017. As of December 31, 2013 and 2012, we had total real estate mortgages receivable with an aggregate carrying value of $8,107 and $1,419, respectively, included in other assets in our consolidated balance sheets.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
Shareholders' Equity	Dec. 31, 2013
Shareholders' Equity	'
Shareholders' Equity	'

	Note 8. Shareholders' Equity

	Share Awards:

	We have common shares available for issuance under the terms of our 2012 Equity Compensation Plan, or the 2012 Plan. The 2012 Plan was adopted in May 2012 and replaced our 2003 Incentive Share Award Plan, or the 2003 Plan. We awarded common shares to our officers and certain employees of RMR in 2013, 2012 and 2011 pursuant to both of these plans. We also awarded each of our Trustees 2,000 common shares in 2013 with an aggregate market value of $201 ($40 per Trustee) on the date of grant, 2,000 common shares in 2012 with an aggregate market value of $226 ($37 per Trustee) on the date of the grant, and 2,000 common shares in 2011 with an aggregate market value of $266 ($53 per Trustee) on the date of the grant, as part of their annual compensation. The common shares awarded to our Trustees vested immediately. The common shares awarded to our officers and certain employees of RMR vest in five equal annual installments beginning on the date of grant. We include the value of awarded shares in general and administrative expenses at the time the awards vest. See Note 12 for further information regarding grants of restricted shares we made to our officers and certain employees of RMR.

	A summary of shares granted and vested under the terms of our 2012 Plan and our 2003 Plan for the years ended December 31, 2013, 2012 and 2011, is as follows:


		Number			Weighted
		of			Average
		Shares			Grant Date
					Fair Value
	Unvested shares at December 31, 2010		70,520		$	27.96
	Granted in 2011		83,050			20.76
	Vested in 2011		(49,955	)		20.79


	Unvested shares at December 31, 2011		103,615			23.32
	Granted in 2012		83,617			15.99
	Vested in 2012		(71,244	)		15.75
	Forfeited in 2012		(1,285	)		18.74


	Unvested shares at December 31, 2012		114,703			19.39
	Granted in 2013		83,450			23.29
	Vested in 2013		(66,639	)		23.06
	Forfeited in 2013		(600	)		22.49


	Unvested shares at December 31, 2013		130,914			20.7





	The 130,914 unvested shares as of December 31, 2013 are scheduled to vest as follows: 47,868 shares in 2014, 40,593 shares in 2015, 27,843 shares in 2016 and 14,610 shares in 2017. As of December 31, 2013, the estimated future compensation expense for the unvested shares was $3,052 based on the closing share price of our common shares on December 31, 2013 of $23.31. The weighted average period over which the compensation expense will be recorded is approximately 22 months. During the years ended December 31, 2013, 2012 and 2011, we recorded $1,758, $1,179 and $1,139, respectively, of compensation expense related to our 2012 Plan and our 2003 Plan. In addition, during the period that SIR was our consolidated subsidiary, we recorded compensation expense related to SIR's equity compensation plan of $355 and $507 for the years ended December 31, 2013 and 2012, respectively.

	At December 31, 2013, 2,833,533 common shares remain available for issuance under the 2012 Plan.

	On January 28, 2014, we granted 2,000 common shares of beneficial interest, par value $0.01 per share, valued at $23.46 per share, the closing price of our common shares on the NYSE on that day, to each of two recently appointed Trustees as part of their annual compensation.

	Share Issuance:

	On February 7, 2014, we issued 12,187 of our common shares to RMR as part of its compensation under our amended and restated business management agreement. See Note 12 for further information regarding this agreement.

	Common Share Distributions:

	In January 2014, we declared a distribution of $0.25 per common share, or $29,597, which we paid on February 21, 2014 to shareholders of record on January 13, 2014. Cash distributions per common share paid by us in 2013, 2012 and 2011, were $1.00, $1.75 and $2.00, respectively. The characterization of our distributions paid in 2013, 2012 and 2011 was 0.00%, 61.72% and 65.90% ordinary income, respectively, 100.00%, 38.28% and 23.54% return of capital, respectively, 0.00%, 0.00% and 7.34% Internal Revenue Code section 1250 gain, respectively, and 0.00%, 0.00% and 3.22% capital gain, respectively. Our revolving credit facility agreement and term loan agreement contain a number of financial and other covenants, including a covenant which restricts our ability to make distributions under certain circumstances. See Note 13 for additional information regarding our revolving credit facility agreement and term loan agreement.

	Preferred Shares:

	Each of our 15,180,000 series D cumulative convertible preferred shares accrue dividends of $1.625, or 6¹/2% per annum of the liquidation amount, payable in equal quarterly payments. Our series D preferred shares are convertible, at the holder's option, into our common shares at an initial conversion rate of 0.480775 common shares per series D preferred share, which is equivalent to an initial conversion price of $52.00 per common share, or 7,298,165 additional common shares at December 31, 2013. On or after November 20, 2011, if our common shares trade at or above the then applicable conversion price, we may, at our option, convert some or all of the series D preferred shares into common shares at the then applicable conversion rate. If a fundamental change occurs, which generally will be deemed to occur upon a change in control of us or a termination of trading of our common shares (or other equity securities into which our series D preferred shares are then convertible), holders of our series D preferred shares will have a special right to convert their series D preferred shares into a number of our common shares per $25.00 liquidation preference, plus accrued and unpaid distributions, divided by 98% of the average closing market price of our common shares for a specified period before such event is effective, unless we exercise our right to repurchase these series D preferred shares for cash, at a purchase price equal to 100% of their liquidation preference, plus accrued and unpaid distributions. The issuance of a large number of common shares as a result of the exercise of this conversion right after a fundamental change may have a dilutive effect on income from continuing operations attributable to CommonWealth REIT common shareholders per share for future periods.

	Each of our 11,000,000 series E preferred shares has a liquidation preference of $25.00 and requires dividends of $1.8125, or 7¹/4% per annum of the liquidation amount, payable in equal quarterly payments. The series E preferred shares are redeemable at our option for $25.00 each plus accrued and unpaid distributions at any time on or after May 15, 2016 or if a change of control occurs which results in our common shares (or the common securities of an acquiring or surviving entity) not being listed or quoted on the NYSE or certain other exchanges or quotation systems. Also, upon the occurrence of such a change of control, holders of series E preferred shares that we do not elect to redeem may at their option convert those series E preferred shares into our common shares (or certain alternative consideration) at a conversion rate generally based on their $25.00 liquidation preference per share, plus accrued and unpaid distributions, and the market price of our common shares at the time of conversion, subject to a cap.

	We have adopted a Shareholders Rights Plan pursuant to which a right to purchase securities is distributable to shareholders in certain circumstances. Each right entitles the holder to purchase or to receive securities or other assets of ours upon the occurrence of certain events. The rights expire and are redeemable at our option. We have determined to accelerate the expiration of the Shareholders Rights Plan, which currently is set to expire on October 17, 2014, to a date soon after resolution of the pending disputes with Related/Corvex.

Cumulative_Other_Comprehensive

Cumulative Other Comprehensive (Loss) Income	12 Months Ended
Cumulative Other Comprehensive (Loss) Income	Dec. 31, 2013
Cumulative Other Comprehensive (Loss) Income	'
Cumulative Other Comprehensive (Loss) Income	'

	Note 9. Cumulative Other Comprehensive (Loss) Income

	The following table presents a roll forward of amounts recognized in cumulative other comprehensive (loss) income by component for the year ended December 31, 2013:


		Year Ended December 31, 2013
		Unrealized			Foreign			Equity in			Total
		Gain (Loss)			Currency			Unrealized
		on Derivative			Translation			Gain (Loss) of
		Instruments			Adjustments			an Investee
	Balances as of December 31, 2012	$	(16,624	)	$	17,071		$	118		$	565


	Other comprehensive income (loss) before reclassifications		(103	)		(43,718	)		(79	)		(43,900	)
	Amounts reclassified from cumulative other comprehensive (loss) income to net loss		5,021			—			(17	)		5,004


	Net current period other comprehensive income (loss)		4,918			(43,718	)		(96	)		(38,896	)


	Balances as of December 31, 2013	$	(11,706	)	$	(26,647	)	$	22		$	(38,331	)





	The following table presents reclassifications out of cumulative other comprehensive income (loss) for the year ended December 31, 2013:


	Year Ended December 31, 2013
	Details about	Amounts Reclassified from			Affected Line Items
	Cumulative Other	Cumulative Other Comprehensive			in the
	Comprehensive Income (Loss) Components	Income (Loss) to Net Loss			Statement of Operations
	Interest rate swap contracts	$	5,021		Interest expense
	Unrealized gains and losses on available for sale securities		(17	)	Equity in earnings of investees


		$	5,004

Noncontrolling_Interest_in_Con

Noncontrolling Interest in Consolidated Subsidiary	12 Months Ended
Noncontrolling Interest in Consolidated Subsidiary	Dec. 31, 2013
Noncontrolling Interest in Consolidated Subsidiary	'
Noncontrolling Interest in Consolidated Subsidiary	'

	Note 10. Noncontrolling Interest in Consolidated Subsidiary

	At December 31, 2013 and 2012, we owned 22,000,000, or approximately 44.2% and 56.0%, respectively, of SIR's outstanding common shares. SIR is a REIT that is focused on owning and investing in net leased, single tenant properties and was a 100% owned subsidiary of ours until the SIR IPO in March 2012, when it became a publicly owned company listed on the NYSE. We are SIR's largest shareholder and SIR was one of our consolidated subsidiaries until July 2, 2013. During the time that SIR was our majority owned consolidated subsidiary (from the date of the SIR IPO to July 2, 2013), the portion of SIR's equity that we did not own is reported as noncontrolling interest in our consolidated balance sheets, and the portion of SIR's net income not allocated to us is reported as noncontrolling interest in our consolidated statements of operations. See Note 12 for additional information regarding the SIR IPO and Note 6 for information regarding the deconsolidation of SIR.

	The following table summarizes the changes in our ownership interest in SIR, while it was our consolidated subsidiary, and the effects on the equity attributable to us during the years ended December 31, 2013 and 2012:



		CommonWealth			Effect on the
		REIT			Equity
		Ownership			Attributable to
		Percentage of			CommonWealth
		SIR After			REIT Common
		Transaction			Shareholders
	Year Ended December 31, 2012:
	Increase in noncontrolling interest related to the SIR IPO in March 2012		70.5	%	($	23,857	)
	Increase in noncontrolling interest related to the issuance of SIR common shares pursuant to its equity compensation plan in September 2012		70.4	%		(253	)
	Increase in noncontrolling interest related to the issuance of SIR common shares in December 2012		56	%		(707	)


					($	24,817	)




	Year Ended December 31, 2013:
	Increase in noncontrolling interest related to the issuance of SIR common shares pursuant to its equity compensation plan in May 2013		55.99	%	$	32

Income_Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2013
Income Taxes	'
Income Taxes	'

	Note 11. Income Taxes

	Our provision for income taxes consists of the following:


		Year Ended December 31,
		2013			2012			2011
	Current:
	State	$	519		$	765		$	542
	Foreign		2,572			199			465


			3,091			964			1,007


	Deferred:
	State		—			—			—
	Foreign		(457	)		2,243			340


			(457	)		2,243			340


	Income tax provision	$	2,634		$	3,207		$	1,347





	A reconciliation of our effective tax rate and the U.S. Federal statutory income tax rate is as follows:


		Year Ended December 31,
		2013			2012			2011
	Taxes at statutory U.S. federal income tax rate		35	%		35	%		35	%
	Dividends paid deduction		(35.00	)%		(35.00	)%		(35.00	)%
	State, local, and foreign income taxes, net of federal tax benefit		(1.71	)%		(4.20	)%		1.22	%


	Effective tax rate		(1.71	)%		(4.20	)%		1.22	%





	Deferred income tax assets and liabilities represent the tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes, and are determined using tax rates expected to be in effect when the deferred income tax assets and liabilities are anticipated to be paid or recovered. At December 31, 2013 and 2012, we had deferred tax assets of $2,601 and $2,329, respectively, and deferred tax liabilities of $3,287 and $3,643, respectively, which primarily relate to different carrying amounts for financial reporting and for Australian income tax purposes related to our properties and operations in Australia. Because we are uncertain of our ability to realize the future benefit of certain Australian loss carry forwards, we have reduced our net deferred income tax assets by a valuation allowance of $511 and $598 as of December 31, 2013 and 2012, respectively.

Related_Person_Transactions

Related Person Transactions	12 Months Ended
Related Person Transactions	Dec. 31, 2013
Related Person Transactions	'
Related Person Transactions	'

	Note 12. Related Person Transactions

	We have adopted written Governance Guidelines that describe the consideration and approval of any related person transactions. Under these Governance Guidelines, we may not enter into any transaction in which any Trustee or executive officer, any member of the immediate family of any Trustee or executive officer or any other related person, has or will have a direct or indirect material interest unless that transaction has been disclosed or made known to our Board of Trustees and our Board of Trustees reviews and approves or ratifies the transaction by the affirmative vote of a majority of the disinterested Trustees, even if the disinterested Trustees constitute less than a quorum. If there are no disinterested Trustees, the transaction must be reviewed and approved or ratified by both (i) the affirmative vote of a majority of our Board of Trustees and (ii) the affirmative vote of a majority of our Independent Trustees. In determining whether to approve or ratify a transaction, our Board of Trustees, or disinterested Trustees or Independent Trustees, as the case may be, also act in accordance with any applicable provisions of our declaration of trust, consider all of the relevant facts and circumstances and approve only those transactions that are fair and reasonable to us and our shareholders. All related person transactions described below were reviewed and approved or ratified by a majority of the disinterested Trustees or otherwise in accordance with our policies and our declaration of trust, each as described above. In the case of transactions with us by RMR employees (other than our Trustees and executive officers) subject to our Code of Business Conduct and Ethics, the employee must seek approval from an executive officer who has no interest in the matter for which approval is being requested. Copies of our Governance Guidelines and Code of Business Conduct and Ethics are available on our website, www.cwhreit.com.

	RMR: We have no employees. Personnel and various services we require to operate our business are provided to us by RMR. We have two agreements with RMR to provide management and administrative services to us: (i) a business management agreement, which relates to our business generally, and (ii) a property management agreement, which relates to our property level operations.

	One of our Managing Trustees, Mr. Barry Portnoy, is Chairman, majority owner and an employee of RMR. Our other Managing Trustee, Mr. Adam Portnoy, who is also our President, is the son of Mr. Barry Portnoy, and an owner, President, Chief Executive Officer and a director of RMR. Each of our other executive officers is also an officer of RMR. Two of our Independent Trustees also serve as independent directors or independent trustees of other public companies to which RMR provides management services. Mr. Barry Portnoy serves as a managing director or managing trustee of those companies and Mr. Adam Portnoy serves as a managing trustee of a majority of those companies. In addition, officers of RMR serve as officers of those companies.

	Our Board of Trustees has given our Compensation Committee, which is comprised exclusively of our Independent Trustees, authority to act on our behalf with respect to our management agreements with RMR. The charter of our Compensation Committee requires the committee to annually review the terms of these agreements, evaluate RMR's performance under the agreements and determine whether to renew, amend or terminate the management agreements.

	In 2013, our Compensation Committee retained FTI Consulting, Inc., a nationally recognized compensation consultant experienced in REIT compensation programs, to assist the committee in developing the terms of the incentive fee payable to RMR under our business management agreement with RMR beginning in 2014. In connection with retaining this consultant, our Compensation Committee determined that the consultant did not have any conflicts of interest which would prevent the consultant from advising the committee.

	On December 19, 2013, we and RMR entered into an amended and restated business management agreement, effective with respect to services performed on and after January 1, 2014. Under the terms of this amended and restated business management agreement:



	•
	The annual amount of the base management fee to be paid to RMR by us for each applicable period will be equal to the lesser of:

	•
	the sum of (a) 0.7% of the average historical cost of our real estate investments during such period up to $250,000, plus (b) 1.0% of the average historical cost of our real estate investments located outside the United States, Puerto Rico and Canada during such period, plus (c) 0.5% of the average historical cost of our real estate investments during such period exceeding $250,000 and the average historical cost of our real estate investments located outside the United States, Puerto Rico and Canada combined; and

	•
	the sum of (a) 0.7% of the average closing price per share of our common shares on the NYSE, during such period, multiplied by the average number of our common shares outstanding during such period, plus the daily weighted average of the aggregate liquidation preference of each class of our preferred shares outstanding during such period, plus the daily weighted average of the aggregate principal amount of our consolidated indebtedness during such period, or, together, our Average Market Capitalization, up to $250,000, plus (b) 1.0% of the average historical cost of our real estate investments located outside the United States, Puerto Rico and Canada during such period, plus (c) 0.5% of our Average Market Capitalization exceeding $250,000 and the average historical cost of our real estate investments located outside the United States, Puerto Rico and Canada during such period combined.

	The average historical cost of our real estate investments will include our consolidated assets invested, directly or indirectly, in equity interests in or loans secured by real estate and personal property owned in connection with such real estate (including acquisition related costs and costs which may be allocated to intangibles or are unallocated), all before reserves for depreciation, amortization, impairment charges or bad debts or other similar noncash reserves. Our investment in SIR (or in any other company which has a management agreement with RMR) is not counted for purposes of calculating the fees payable by us to RMR.



	•
	Although the fee calculation is stated in annual percentages, the base management fee is paid monthly to RMR, ninety percent (90%) in cash and ten percent (10%) in our common shares, which shall be fully-vested when issued. The number of our common shares to be issued in payment of the base management fee for each month is equal to the value of 10% of the total base management fee for that month divided by the average daily closing price of our common shares during that month.

	•
	The incentive management fee which may be earned by RMR for an annual period will be an amount, subject to a cap based on the value of our outstanding common shares, equal to 12% of the product of (a) our equity market capitalization on the last trading day on the year immediately prior to the relevant measurement period, and (b) the amount (expressed as a percentage) by which the total returns per share realized by the holders of our common shares (i.e., share price appreciation plus dividends) exceeds the total shareholder return of the SNL Office REIT Index (in each case subject to certain adjustments) for the relevant measurement period. The measurement periods are generally three-year periods ending with the year for which the incentive management fee is being calculated, with shorter periods applicable in the case of the calculation of the incentive management fee for 2014 (one year) and 2015 (two years).

	•
	The incentive management fee is payable in our common shares, with one-third of our common shares issued in payment of an incentive management fee vested on the date of issuance, and the remaining two-thirds vesting thereafter in two equal annual installments. If the issuance of common shares in payment of a portion of the base management fee or incentive management fee would be limited by applicable law and regulations, such portion of the applicable fee will instead be paid in cash.

	•
	RMR and certain eligible transferees of our common shares issued in payment of the base management fee or incentive management fee are entitled to demand registration rights, exercisable not more frequently than twice per year, and to "piggy-back" registration rights, with certain expenses to be paid by us. We and applicable selling shareholders also have agreed to indemnify each other (and their officers, trustees, directors and controlling persons) against certain liabilities, including liabilities under the Securities Act in connection with any such registration.

	The terms of the amended and restated business management agreement described above were approved by our Compensation Committee, which is comprised solely of our Independent Trustees, and the terms of the incentive fee were developed by our Compensation Committee in consultation with FTI Consulting, Inc., an independent compensation consultant.

	For 2013, 2012 and 2011, our business management agreement provided for the base business management fee to be paid to RMR at an annual rate equal to (a) 0.7% of the historical cost of our real estate investments, as described in the business management agreement, located in the United States, Puerto Rico or Canada, for the first $250,000 of such investments, and 0.5% thereafter, plus (b) 1.0% of the historical cost of our real estate investments located outside the United States, Puerto Rico and Canada. In addition, for 2013, 2012 and 2011, our business management agreement provided for RMR to be paid an incentive fee equal to 15% of the product of (i) the weighted average of our common shares outstanding on a fully diluted basis during a fiscal year and (ii) the excess, if any, of the FFO Per Share, as defined in the business management agreement, for such fiscal year over the FFO Per Share for the preceding fiscal year. Our investments in GOV and SIR, which are described below, were not counted for purposes of determining the business management fees payable by us to RMR; however, we reported the business management fees payable to RMR by SIR in our consolidated 2012 results and 2013 results until we deconsolidated our investment in SIR on July 2, 2013. The business management fees we and SIR (while SIR was a consolidated subsidiary of ours) recognized on a consolidated basis were $43,279 and $43,646 for 2013 and 2012, respectively, and for 2011, the aggregate business management fees we recognized were $39,203. These amounts are included in general and administrative expenses and income from discontinued operations, as appropriate, in our consolidated financial statements. No incentive fees were paid by us to RMR for 2013, 2012 or 2011.

	Our property management agreement with RMR provides for management fees equal to 3.0% of gross collected rents and construction supervision fees for construction equal to 5.0% of construction costs. The aggregate property management and construction supervision fees we and SIR (while SIR was a consolidated subsidiary of ours) recognized on a consolidated basis were $32,460 and $33,689 for 2013 and 2012, respectively, and for 2011, the aggregate property management and construction supervision fees that we recognized were $30,315. These amounts are included in operating expenses and income from discontinued operations or have been capitalized, as appropriate, in our consolidated financial statements.

	MacarthurCook Fund Management Limited, or MacarthurCook, previously provided us with business and property management services related to our Australian properties. Our contract with MacarthurCook terminated on January 31, 2013, and on that date we entered into a business and property management agreement, or the Australia Management Agreement with RMR Australia Asset Management Pty Limited, or RMR Australia, for the benefit of CWH Australia Trust (formerly the MacarthurCook Industrial Property Fund), a subsidiary of ours, or CWHAT. The terms of the Australia Management Agreement are substantially similar to the terms of the management agreement we had with MacarthurCook. RMR Australia is owned by our Managing Trustees and it has been granted an Australian financial services license by the Australian Securities & Investments Commission. The Australia Management Agreement provides for compensation to RMR Australia for business management and real estate investment services at an annual rate equal to 0.5% of the average historical cost of CWHAT's real estate investments, as described in the Australia Management Agreement. The Australia Management Agreement also provides for additional compensation to RMR Australia (i) for property management services at an annual rate equal to 50% of the difference between 3.0% of collected gross rents and the aggregate of all amounts paid or payable by or on behalf of CWHAT to third party property managers, and (ii) for construction supervision services at an annual rate equal to 50% of the difference between 5.0% of constructions costs and any amounts paid to third parties for construction management and/or supervision. Similar to our prior arrangement with respect to fees we paid to MacarthurCook, RMR has agreed to waive half of the fees payable by us under our property management agreement with RMR and half of the business management fees otherwise payable by us under our business management agreement with RMR related to real estate investments that are subject to the Australia Management Agreement for so long as the Australia Management Agreement is in effect and we or any of our subsidiaries are paying the fees under that agreement. The Australia Management Agreement was approved by our Compensation Committee, which is comprised solely of Independent Trustees. The aggregate business and property management fees we recognized pursuant to the Australia Management Agreement during 2013 were $1,626, which amount is equal to the fees waived by RMR and excluded from the amounts that were payable to RMR during 2013.

	For January 2013 and the years 2012 and 2011, with respect to our investments in Australia, RMR agreed to waive half of the fees payable by us under our property management agreement and half of the business management fees related to real estate investments located outside of the United States, Puerto Rico and Canada, so long as our business and property management agreement with MacarthurCook with respect to those investments was in effect and we or any of our subsidiaries were paying fees under that agreement. MacarthurCook earned $161, $1,814 and $1,856 in January 2013 and the years 2012 and 2011, respectively, with respect to our Australian properties, which amounts are equal to the fees waived by RMR and excluded from the amounts that were payable to RMR during those periods.

	RMR also provides internal audit services to us in return for our share of the total internal audit costs incurred by RMR for us and other publicly owned companies managed by RMR and its affiliates, which amounts are subject to approval by our Compensation Committee. Our Audit Committee appoints our Director of Internal Audit. Our and SIR's (while SIR was a consolidated subsidiary of ours) share of RMR's costs of providing this internal audit function was, on a consolidated basis, approximately $296, $355 and $240 for 2013, 2012 and 2011, respectively, which amounts are included in general and administrative expenses in our consolidated financial statements. These allocated costs are in addition to the business and property management fees we and SIR paid to RMR.

	We are generally responsible for all of our operating expenses, including certain expenses incurred by RMR on our behalf. We are generally not responsible for payment of RMR's employment, office or administration expenses incurred to provide management services to us, except for the employment and related expenses of RMR employees who provide on-site property management services at our properties and our share of the staff employed by RMR who perform our internal audit function. Pursuant to our amended and restated business management agreement, RMR may from time to time negotiate on our behalf with certain third party vendors and suppliers for the procurement of services to us. As part of this arrangement, we may enter agreements with RMR and other companies to which RMR provides management services for the purpose of obtaining more favorable terms from such vendors and suppliers.

	The current terms of both our amended and restated business management agreement with RMR and our property management agreement with RMR end on December 31, 2014 and automatically renew for successive one year terms unless we or RMR give notice of non-renewal before the end of an applicable term. We or RMR may terminate either agreement upon 60 days' prior written notice, and RMR may also terminate the property management agreement upon five business days' notice if we undergo a change of control, as defined in the property management agreement.

	Under our amended and restated business management agreement with RMR, we acknowledge that RMR may engage in other activities or businesses and act as the manager to any other person or entity (including other REITs) even though such person or entity has investment policies and objectives similar to ours and we are not entitled to preferential treatment in receiving information, recommendations and other services from RMR. Previously our business management agreement had provided that, with certain exceptions, if we determined to offer for sale or other disposition any real property that, at such time, is of a type within the investment focus of another REIT to which RMR provides management services, we would first offer that property for purchase or disposition to that REIT and negotiate in good faith for such purchase or disposition. This right of first offer provision was eliminated when the business management agreement was amended and restated on December 19, 2013.

	RMR also leases from us office space for eleven of its regional offices. We earned approximately $828, $564 and $566 in rental income from RMR in 2013, 2012 and 2011, respectively, with respect to approximately 32,500 square feet of office space, which we believe was commercially reasonable rent for this office space, not all of which was leased to RMR for the entire three-year period. These leases are terminable by RMR if our management agreements with RMR are terminated.

	Under our share award plans, we grant restricted shares to certain employees of RMR, some of whom are our officers. We granted a total of 73,450 restricted shares with an aggregate value of $1,742, 71,617 restricted shares with an aggregate value of $1,111 and 73,050 restricted shares with an aggregate value of $1,458 to such persons in 2013, 2012 and 2011, respectively, based upon the closing price of our common shares on the NYSE on the dates of grants. One fifth of those restricted shares vested on the grant dates and one fifth vests on each of the next four anniversaries of the grant dates. These share grants to RMR employees are in addition to the fees we pay to RMR. On occasion, we have entered into arrangements with former employees of RMR in connection with the termination of their employment with RMR, providing for the acceleration of vesting of restricted shares previously granted to them under our share award plan. Additionally, each of our President, Treasurer and Chief Financial Officer and Senior Vice President and Chief Operating Officer received grants of restricted shares of other companies to which RMR provides management services in their capacities as officers of RMR.

GOV: GOV was formerly our 100% owned subsidiary. Our Managing Trustees are also managing trustees of GOV. RMR provides management services to both us and GOV. GOV's executive officers are officers of RMR.

In 2009, GOV completed an initial public offering pursuant to which GOV ceased to be a majority owned subsidiary of ours. To facilitate this offering, we and GOV entered into a transaction agreement that governs our separation from and relationship with GOV. Pursuant to this transaction agreement, among other things, we and GOV agreed that, so long as we own in excess of 10% of GOV's outstanding common shares, we and GOV engage the same manager or we and GOV have any common managing trustees: (i) we will not acquire ownership of properties that are majority leased to government tenants, unless a majority of GOV's independent trustees who are not also our Trustees have determined that GOV not make the acquisition; (ii) GOV will not acquire ownership of office or industrial properties that are not majority leased to government tenants, unless a majority of our Independent Trustees who are not also GOV's trustees have determined that we not make the acquisition; and (iii) GOV will have a right of first refusal to acquire any property owned by us that we determine to divest if the property is then majority leased to a government tenant, which right of first refusal will also apply in the event of an indirect sale of any such properties as a result of a change of control of us. The provisions described in (i) and (ii) do not prevent GOV from continuing to own and lease its current properties or properties otherwise acquired by GOV that cease to be majority leased to government tenants following the termination of government tenancies; and, similarly, the provisions described in (i) and (ii) also do not prohibit us from leasing our current or future properties to government tenants. We and GOV also agreed that disputes arising under the transaction agreement may be resolved by binding arbitration.

On March 15, 2013, we sold all of our 9,950,000 common shares of GOV in a public offering for net proceeds (after deducting underwriters' discounts and commissions and expenses) of $239,576 and we realized a gain of $66,293. In connection with this public offering, on March 11, 2013, we entered into a registration agreement with GOV under which we agreed to pay all expenses incurred by GOV relating to the registration and sale of our GOV common shares. We incurred $310 of reimbursements payable to GOV pursuant to this agreement. In addition, under the registration agreement, GOV agreed to indemnify us and our officers, Trustees and controlling persons, and we agreed to indemnify GOV and its officers, trustees and controlling persons, against certain liabilities related to the public offering, including liabilities under the Securities Act.

SIR: SIR was formerly our 100% owned subsidiary. We are SIR's largest shareholder and, until July 2, 2013, SIR was one of our consolidated subsidiaries. As of December 31, 2013, we owned 22,000,000 common shares of SIR, which represents approximately 44.2% of SIR's outstanding common shares. Our Managing Trustees are also managing trustees of SIR and our Treasurer and Chief Financial Officer also serves as the treasurer and chief financial officer of SIR. In addition, one of our Independent Trustees is an independent trustee of SIR. RMR provides management services to both us and SIR. SIR's executive officers are officers of RMR.

On March 12, 2012, SIR completed an initial public offering pursuant to which it issued 9,200,000 of its common shares for net proceeds (after deducting underwriters' discounts and commissions and expenses) of $180,814. SIR applied those net proceeds, along with proceeds from drawings under SIR's revolving credit facility, to repay in full a $400,000 demand promissory note that we received from SIR on February 16, 2012, along with 22,000,000 SIR common shares (including SIR common shares that had been previously issued to us in connection with SIR's formation), in exchange for our transfer to SIR of 79 properties (251 separate buildings or land parcels with a combined approximately 21,400,000 rentable square feet). SIR also reimbursed us for costs that we incurred in connection with SIR's organization and preparation for the SIR IPO.

In connection with the SIR IPO, we and SIR entered into a transaction agreement that governs our separation from and relationship with SIR. The transaction agreement provides that, among other things, (1) the current assets and liabilities of the 79 properties that we transferred to SIR, as of the time of closing of the SIR IPO, were settled between us and SIR so that we will retain all pre-closing current assets and liabilities and SIR will assume all post-closing current assets and liabilities and (2) SIR will indemnify us with respect to any liability relating to any property transferred by us to SIR, including any liability which relates to periods prior to SIR's formation, other than the pre-closing current assets and current liabilities that we retained with respect to the 79 transferred properties.

On March 25, 2013, we entered into a registration agreement with SIR, pursuant to which SIR agreed to, among other things, file a registration statement with respect to an offering of up to all of the 22,000,000 common shares of SIR that we own, and we agreed to pay all expenses incurred by SIR relating to the registration and sale of the shares in an offering. SIR's obligation to register the shares for resale in an offering is subject to certain conditions and may be terminated in certain circumstances, in each case, as described in the registration agreement. We incurred and paid $636 of reimbursements to SIR pursuant to this agreement. SIR agreed to indemnify us and our officers, Trustees and controlling persons, and we agreed to indemnify SIR and its officers, trustees and controlling persons, against certain liabilities in connection with an offering, including liabilities under the Securities Act. SIR has an effective registration statement on Form S-3, which permits resales of SIR's shares by selling shareholders, pursuant to which, and subject to the terms of the registration agreement, we may be able to sell our SIR common shares in a registered offering.

SNH: SNH was formerly our 100% owned subsidiary. It was spun off to our shareholders in 1999. As of December 31, 2013, SNH owns 250,000 of our common shares. Our Managing Trustees are also managing trustees of SNH. In addition, one of our Independent Trustees is an independent trustee of SNH. RMR provides management services to both us and SNH. SNH's executive officers are officers of RMR and SNH's President and Chief Operating Officer is a director of RMR. The sale agreements and related transactions between us and SNH described below were negotiated and approved by special committees of each company's board of trustees comprised solely of Independent Trustees who were not also Independent Trustees of the other company.

At the time of SNH's spin off, we and SNH entered into a transaction agreement pursuant to which, among other things, we and SNH agreed that so long as we own 10% or more of SNH's common shares, we and SNH engage the same manager or we and SNH have any common managing trustees: (1) we will not make any investment in senior apartments, congregate communities, assisted living properties, nursing homes or other healthcare properties, but excluding medical office properties, medical clinics and clinical laboratory buildings, or MOBs, without the prior approval of a majority of SNH's independent trustees, and (2) SNH will not make any investment in office buildings, warehouses or malls, including MOBs, without the prior approval of a majority of our Independent Trustees. In 2008, in connection with our agreement to sell 45 MOBs to SNH, we and SNH amended the transaction agreement to permit SNH, rather than us, to invest in MOBs and we granted SNH a right of first refusal to purchase up to 45 identified MOBs we then owned if we decided to sell those properties.

Between November 2010 and January 2011, we sold 15 properties (27 buildings) (approximately 2,803,000 square feet), which were majority leased to tenants in medical related businesses, to SNH for an aggregate sale price of $470,000, excluding closing costs. We recognized net gains totaling approximately $168,272 from these sales. In September 2011, we sold to SNH seven additional properties (13 buildings) (approximately 1,310,000 square feet), which were majority leased to tenants in medical related businesses, for an aggregate sale price of $167,000, excluding closing costs, and we recognized net gains totaling $7,846 from these sales. In connection with our September 2011 sale of seven properties to SNH, we and SNH terminated the SNH right as substantially all of the properties that were subject to that right of first refusal had been purchased by SNH. Our sale agreements with SNH include arbitration provisions for the resolution of disputes.

AIC: We, RMR, GOV, SIR, SNH and three other companies to which RMR provides management services each currently own 12.5% of AIC. A majority of our Trustees and most of the trustees and directors of the other AIC shareholders currently serve on the board of directors of AIC. RMR provides management and administrative services to AIC pursuant to a management and administrative services agreement with AIC. Our Governance Guidelines provide that any material transaction between us and AIC shall be reviewed, authorized and approved or ratified by the affirmative votes of both a majority of our Board of Trustees and a majority of our Independent Trustees. The shareholders agreement among us, the other shareholders of AIC and AIC includes arbitration provisions for the resolution of disputes.

As of December 31, 2013, we have invested approximately $5,209 in AIC since we became an equity owner of AIC in 2008. We use the equity method to account for this investment because we believe that we have significant influence over AIC as a majority of our Trustees are also directors of AIC. For the period that SIR was both a shareholder of AIC and our consolidated subsidiary, from May 2012 until July 2, 2013, our consolidated financial statements include SIR's equity investment interest in AIC. In June 2013, we and the other shareholders of AIC purchased a one-year property insurance policy providing $500,000 of coverage pursuant to an insurance program arranged by AIC and with respect to which AIC is a reinsurer of certain coverage amounts. We paid AIC a premium, including taxes and fees, of approximately $5,984 in connection with that policy, which amount may be adjusted from time to time as we acquire or dispose of properties that are included in the policy. Our annual premiums for this property insurance in 2012 and 2011 were $6,560 and $6,697, respectively, before adjustments made for acquisitions or dispositions we made during those periods. We periodically consider the possibilities for expanding our insurance relationships with AIC to include other types of insurance and may in the future participate in additional insurance offerings AIC may provide or arrange. We may invest additional amounts in AIC in the future if the expansion of this insurance business requires additional capital, but we are not obligated to do so. By participating in this insurance business with RMR and the other companies to which RMR provides management services, we expect that we may benefit financially by possibly reducing our insurance expenses or by realizing our pro rata share of any profits of this insurance business.

Indemnification and Directors' and Officers' Liability Insurance: In July 2013, we, RMR, GOV, SIR, SNH and two other companies to which RMR provides management services purchased a combined directors' and officers' liability insurance policy providing $10,000 in aggregate primary non-indemnifiable coverage and $5,000 in aggregate excess coverage. We paid a premium of approximately $133 in connection with this policy.

Pursuant to our declaration of trust and separate indemnification agreements, we have advanced amounts incurred for legal fees and costs on behalf of certain of our current and former Trustees and officers with respect to the legal proceedings described in Part I, Item 3, "Legal Proceedings" in this Annual Report on Form 10-K. Pursuant to indemnification provisions in our business and property management agreements with RMR, we have also advanced amounts incurred for legal fees and costs on behalf of RMR for claims brought against RMR in its capacity as our business and property manager with respect to certain legal proceedings described in Part I, Item 3, "Legal Proceedings." In 2013, we incurred approximately $30,392 in such legal fees and costs, including our costs.

Indebtedness

Indebtedness	12 Months Ended
Indebtedness	Dec. 31, 2013
Indebtedness	'
Indebtedness	'

	Note 13. Indebtedness

	At December 31, 2013, our outstanding indebtedness, and at December 31, 2012, our and SIR's (when SIR was a consolidated subsidiary of ours) outstanding indebtedness, included the following:


			December 31,
			2013			2012
	Unsecured revolving credit facility, due October 2015, at LIBOR plus a premium		$	235,000		$	297,000
	Unsecured revolving credit facility, due March 2016, at LIBOR plus a premium⁽¹⁾			—			95,000
	Unsecured term loan, due December 2016, at LIBOR plus a premium			500,000			500,000
	Unsecured term loan, due July 2017, at LIBOR plus a premium⁽¹⁾			—			350,000
	Senior Notes, due 2014 at 5.75%			—			244,655
	Senior Notes, due 2015 at 6.40%			33,440			186,000
	Senior Notes, due 2015 at 5.75%			138,773			250,000
	Senior Notes, due 2016 at 6.25%			139,104			400,000
	Senior Notes, due 2017 at 6.25%			250,000			250,000
	Senior Notes, due 2018 at 6.65%			250,000			250,000
	Senior Notes, due 2019 at 7.50%			125,000			125,000
	Senior Notes, due 2020 at 5.875%			250,000			250,000
	Senior Notes, due 2042 at 5.75%			175,000			175,000
	Mortgage Notes Payable, due 2014 at 4.95%			12,040			12,356
	Mortgage Notes Payable, due 2015 at 5.99%			7,987			8,272
	Mortgage Notes Payable, due 2015 at 5.78%⁽²⁾			—			8,980
	Mortgage Notes Payable, due 2016 at 5.235%			116,000			116,000
	Mortgage Notes Payable, due 2016 at 5.689%⁽¹⁾			—			7,500
	Mortgage Notes Payable, due 2016 at 5.76%			—			7,474
	Mortgage Notes Payable, due 2016 at 6.03%			40,334			40,854
	Mortgage Notes Payable, due 2016 at 6.29%			144,522			146,264
	Mortgage Notes Payable, due 2016 at 7.36%			10,804			11,302
	Mortgage Notes Payable, due 2017 at 5.67%			41,275			41,275
	Mortgage Notes Payable, due 2017 at 5.68%			265,000			265,000
	Mortgage Notes Payable, due 2017 at 5.95%⁽¹⁾			—			18,447
	Mortgage Notes Payable, due 2019 at LIBOR plus a premium⁽³⁾			173,247			174,870
	Mortgage Notes Payable, due 2021 at 5.69%			28,391			28,793
	Mortgage Notes Payable, due 2021 at 5.30%			39,598			40,185
	Mortgage Notes Payable, due 2022 at 6.75%			3,456			3,759
	Mortgage Notes Payable, due 2023 at 6.14%⁽²⁾			—			12,650
	Mortgage Notes Payable, due 2026 at 5.71%			7,240			7,637


				2,986,211			4,324,273
	Unamortized net premiums and discounts			19,199			25,548


			$	3,005,410		$	4,349,821






	-1
	Represents indebtedness of SIR when SIR was a consolidated subsidiary of ours.

	-2
	These mortgage notes are included in liabilities related to properties held for sale at December 31, 2013. See Note 4 for additional information regarding our properties held for sale.

	-3
	Interest on this loan is payable at a spread over LIBOR but has been fixed for the first seven years to December 1, 2016 by a cash flow hedge which sets the rate at approximately 5.66%.

	Prepayments:

In March 2013, we purchased a total of $670,295 of the outstanding principal amount of the following senior notes for $726,151, excluding transaction costs, pursuant to a tender offer:


Senior Note		Principal			Purchase
Senior Note		Principal			Price
5.75% Senior Notes due February 15, 2014		$	145,612		$	148,746
6.40% Senior Notes due February 15, 2015			152,560			164,140
5.75% Senior Notes due November 1, 2015			111,227			121,047
6.25% Senior Notes due August 15, 2016			260,896			292,218


		$	670,295		$	726,151





In connection with the purchase of these senior notes, we recognized a combined loss on early extinguishment of debt totaling $60,027, which includes the write-off of unamortized discounts and deferred financing fees and expenses.

In October 2013, we prepaid at par all $99,043 of our 5.75% unsecured senior notes due 2014, using borrowings under our revolving credit facility. In addition, we prepaid $7,093 of 5.76% mortgage debt in December 2013, in connection with the sale of the related property. In connection with the prepayment of mortgage debt, we recorded a loss on early extinguishment of debt totaling $1,011 from a prepayment premium and the write off of unamortized discount.

Unsecured Revolving Credit Facility and Unsecured Term Loan:

We have a $750,000 unsecured revolving credit facility that is available for general business purposes, including acquisitions. The maturity date of our revolving credit facility is October 19, 2015 and, subject to the payment of an extension fee and meeting certain other conditions, includes an option for us to extend the stated maturity date of our revolving credit facility by one year to October 19, 2016. In addition, our revolving credit facility includes a feature under which maximum borrowings may be increased to up to $1,500,000 in certain circumstances. Borrowings under our revolving credit facility bear interest at LIBOR plus a premium, which was 150 basis points as of December 31, 2013 and 2012. We also pay a facility fee of 35 basis points per annum on the total amount of lending commitments under our revolving credit facility. Both the interest rate premium and the facility fee are subject to adjustment based upon changes to our credit ratings. As of December 31, 2013 and 2012, the interest rate payable on borrowings under our revolving credit facility was 1.7%. The weighted average interest rate for borrowings under our revolving credit facility was 1.7% and 1.5% for the years ended December 31, 2013 and 2012, respectively. As of December 31, 2013, we had $235,000 outstanding and $515,000 available under our revolving credit facility.

We also have a $500,000 unsecured term loan that matures in December 2016 and is prepayable without penalty at any time. Our term loan includes a feature under which maximum borrowings may be increased to up to $1,000,000 in certain circumstances. Our term loan bears interest at a rate of LIBOR plus a premium, which was 185 basis points as of December 31, 2013 and 2012. The interest rate premium is subject to adjustment based upon changes to our credit ratings. As of December 31, 2013 and 2012, the interest rate for the amount outstanding under our term loan was 2.0% and 2.1%, respectively. The weighted average interest rate for the amount outstanding under our term loan was 2.0% and 1.8% for the years ended December 31, 2013 and 2012, respectively.

Our revolving credit facility agreement and our term loan agreement provide for a right to accelerate payment of all amounts due thereunder upon the occurrence and continuation of certain events of default, including a change of control of us and RMR ceasing to act as our business manager and property manager, unless waived by our lenders holding two-thirds of the aggregate credit exposure under the applicable agreement. If the Related/Corvex consent solicitation is successful in removing our entire Board of Trustees, such removal would constitute an event of default under our revolving credit facility and term loan agreements. Either such default, unless waived, would give either the administrative agent or the lenders holding 51% of the aggregate credit exposure under the applicable agreement the right to accelerate payment of all amounts we may owe under such agreement. Such events may also constitute an event of default under certain of our mortgage loans and may trigger cross default provisions of our public debt indenture and related supplements. Related/Corvex have publicly stated that if their consent solicitation is successful in removing our entire Board of Trustees, they will offer to buy 51% of the debt outstanding under our revolving credit facility and term loan agreements at par value to prevent the acceleration of such loans. However, waivers of these defaults under our revolving credit facility and term loan agreements require the approval of the holders of two-thirds of the aggregate credit exposure under the applicable agreement. We can provide no assurance that, in such event, Related/Corvex will be successful in buying any of our outstanding debts or credit commitments, preventing any demand for the immediate payment of these loans or procuring waivers of any default that may be required for the Company to continue to pay dividends or other distributions or repurchase shares. The lenders under these agreements may not be willing to waive any event of default particularly if we have no Trustees.

Credit Facility and Term Loan Debt Covenants:

Our public debt indenture and related supplements, our revolving credit facility agreement and our term loan agreement contain a number of financial and other covenants, including covenants that restrict our ability to incur indebtedness or to make distributions under certain circumstances and require us to maintain financial ratios and a minimum net worth. At December 31, 2013, we believe we were in compliance with all of our respective covenants under our public debt indenture and related supplements, our revolving credit facility and our term loan agreements.

At December 31, 2013, 13 of our continuing properties (18 buildings) costing $1,269,185 with an aggregate net book value of $1,109,259 secured mortgage notes totaling $914,510 (including net premiums and discounts) maturing from 2014 through 2026. In addition, we had mortgage debt secured by two properties (three buildings) classified as held for sale totaling $20,018 (including net premiums and discounts).

The required principal payments due during the next five years and thereafter under all of our outstanding debt at December 31, 2013, excluding principal payments totaling $20,402 for mortgage debt related to properties classified as held for sale, are as follows:


2014		$	18,826
2015			421,821
2016			948,708
2017			560,592
2018			254,614
Thereafter			781,650


		$	2,986,211

Fair_Value_of_Assets_and_Liabi

Fair Value of Assets and Liabilities	12 Months Ended
Fair Value of Assets and Liabilities	Dec. 31, 2013
Fair Value of Assets and Liabilities	'
Fair Value of Assets and Liabilities	'



	Note 14. Fair Value of Assets and Liabilities

	The table below presents certain of our assets and liabilities measured at fair value during 2013, categorized by the level of inputs used in the valuation of each asset and liability:


					Fair Value at Reporting Date Using
	Description	Total			Quoted Prices in			Significant Other			Significant
					Active Markets for			Observable Inputs			Unobservable
					Identical Assets			(Level 2)			Inputs
					(Level 1)						(Level 3)
	Recurring Fair Value Measurements:
	Effective portion of interest rate contracts⁽¹⁾	$	(11,706	)	$	—		$	(11,706	)	$	—
	Non-Recurring Fair Value Measurements:
	Properties held for sale⁽²⁾	$	464,299		$	—		$	—		$	464,299


	-1
	The fair value of our interest rate swap contracts is determined using the net discounted cash flows of the expected cash flows of each derivative based on the market based interest rate curve (level 2 inputs) and adjusted for our credit spread and the actual and estimated credit spreads of the counterparties (level 3 inputs). Although we have determined that the majority of the inputs used to value our derivatives fall within level 2 of the fair value hierarchy, the credit valuation adjustments associated with our derivatives utilize level 3 inputs, such as estimates of current credit spreads, to evaluate the likelihood of default by us and the counterparties. As of December 31, 2013, we have assessed the significance of the impact of the credit valuation adjustments on the overall valuation of our derivative positions and have determined that the credit valuation adjustments are not significant to the overall valuation of our derivatives. As a result, we have determined that our derivative valuations in their entirety are classified as level 2 inputs in the fair value hierarchy.

	-2
	As of December 31, 2013, we recorded a net loss on asset impairment totaling $204,036 (excluding $23,086 of asset impairment recorded on properties sold during 2013) for three of our CBD properties (four buildings) and 36 of our suburban properties (89 buildings) to reduce the aggregate carrying value of these properties from $668,335 to their estimated fair value of $471,457, reflected in the table below, less costs to sell of $464,299. All of these properties were classified as held for sale as of December 31, 2013. We used third party broker information, independent appraisals and sales comparables (level 3 inputs), in determining the fair value of these properties. The valuation techniques and significant unobservable inputs used for our level 3 fair value measurements at December 31, 2013 were as follows:


	Description	Fair Value at			Primary		Unobservable		Range
		December 31,			Valuation		Inputs		(Weighted Average)
		2013			Techniques
	Properties held for sale on which we recognized impairment losses	$	471,457		Discounted cash flows		Discount rate		9% - 12% (10.3%)
							Exit capitalization rate		8% - 10% (8.8%)

	We are exposed to certain risks relating to our ongoing business operations, including the effect of changes in foreign currency exchange rates and interest rates. The only risk we currently manage by using derivative instruments is a part of our interest rate risk. Although we have not done so as of December 31, 2013, and have no present intention to do so, we may manage our Australian currency exchange exposure by borrowing in Australian dollars or using derivative instruments in the future, depending on the relative significance of our business activities in Australia at that time. We have interest rate swap agreements to manage our interest rate risk exposure on $173,247 of mortgage debt due 2019, which require interest at a premium over LIBOR. The interest rate swap agreements utilized by us qualify as cash flow hedges and effectively modify our exposure to interest rate risk by converting our floating interest rate debt to a fixed interest rate basis for this loan through December 1, 2016, thus reducing the impact of interest rate changes on future interest expense. These agreements involve the receipt of floating interest rate amounts in exchange for fixed rate interest payments over the life of the agreements without an exchange of the underlying principal amount. The fair value of our derivative instruments increased by $4,918 during the year ended December 31, 2013 and decreased by $828 during the year ended December 31, 2012, based primarily on changes in market interest rates. As of December 31, 2013 and 2012, the fair value of these derivative instruments included in accounts payable and accrued expenses and cumulative other comprehensive (loss) income in our consolidated balance sheets totaled ($11,706) and ($16,624), respectively. We may enter additional interest rate swaps or hedge agreements to manage some of our additional interest rate risk associated with our floating rate borrowings. The table below presents the effects of our interest rate derivatives on our consolidated statements of operations and consolidated statements of comprehensive (loss) income for the years ended December 31, 2013, 2012 and 2011:


		Year Ended December 31,
		2013			2012			2011
	Balance at beginning of year	($	16,624	)	($	15,796	)	($	6,956	)
	Amount of loss recognized in cumulative other comprehensive (loss) income		(103	)		(5,790	)		(13,804	)
	Amount of loss reclassified from cumulative other comprehensive (loss) income into interest expense		5,021			4,962			4,964


	Unrealized gain (loss) on derivative instruments		4,918			(828	)		(8,840	)


	Balance at end of year	($	11,706	)	($	16,624	)	($	15,796	)





	Over the next 12 months, we estimate that approximately $4,862 will be reclassified from cumulative other comprehensive income as an increase to interest expense.

	In addition to the assets and liabilities described in the above table, our financial instruments include our cash and cash equivalents, rents receivable, investment in direct financing lease receivable, real estate mortgages receivable, restricted cash, revolving credit facility, senior notes and mortgage notes payable, accounts payable and accrued expenses, rent collected in advance, security deposits and amounts due to related persons. At December 31, 2013 and 2012, the fair values of these additional financial instruments, excluding mortgage debt related to properties held for sale, were not materially different from their carrying values, except as follows:


		December 31, 2013						December 31, 2012
		Carrying			Fair			Carrying			Fair
		Amount			Value			Amount			Value
	Senior notes and mortgage notes payable	$	2,097,164		$	2,143,834		$	2,932,951		$	3,181,522

	The fair values of our senior notes and mortgage notes payable are based on estimates using discounted cash flow analyses and currently prevailing interest rates adjusted by credit risk spreads (level 3 inputs).

Other financial instruments that potentially subject us to concentrations of credit risk consist principally of rents receivable; however, as of December 31, 2013, no single tenant of ours is responsible for more than 3% of our total rents.

We maintain derivative financial instruments, including interest rate swaps, with major financial institutions and monitor the amount of credit exposure to any one counterparty.

Segment_Information

Segment Information	12 Months Ended
Segment Information	Dec. 31, 2013
Segment Information	'
Segment Information	'

	Note 15. Segment Information

	Our primary business is the ownership and operation of a nationwide portfolio of properties. We account for each of our individual properties as a separate operating segment. We have aggregated our separate operating segments into two reportable segments based on our primary method of internal reporting: CBD properties and suburban properties. More than 90% our CBD and suburban properties are office properties. As a result of our deconsolidation of SIR in 2013, we no longer include "industrial and other" among our reportable segments. Each of our reportable segments includes within its segments properties with similar operating and economic characteristics that are subject to unique supply and demand conditions. Geographic regions described in our prior year financial statements were eliminated primarily because one of these regions included properties owned primarily by SIR which are no longer included in our consolidated financial statements as of December 31, 2013, and the remaining two regions no longer represent a meaningful portion of our consolidated portfolio. See Note 6 for financial information relating to SIR. Our operating segments (i.e., our individual properties) are managed and operated consistently in accordance with our standard operating procedures, and our management responsibilities do not vary significantly from location to location based on the size of the property or geographic location within each primary reporting segment. We use property net operating income, or NOI, to evaluate the performance of our operating segments. We define NOI as income from our real estate including lease termination fees received from tenants less our property operating expenses, which expenses include property marketing costs. NOI excludes amortization of capitalized tenant improvement costs and leasing commissions.

	As of December 31, 2013, we owned 38 CBD properties (51 buildings) and 87 suburban properties (144 buildings), excluding properties classified as held for sale. Prior periods have been restated to reflect properties reclassified to discontinued operations during 2013.

	The following items are accounted for on a corporate level and are not allocated among our segments: depreciation and amortization expense, general and administrative expense, loss on asset impairment, acquisition related costs, interest and other income and expense, loss on early extinguishment of debt, gain on sale of equity investment, gain on issuance of shares by an equity investee, income tax expense, equity in earnings of investees, income (loss) from discontinued operations and gain on sale of properties. The accounting policies of our segments are the same as the accounting policies described in our summary of significant accounting policies.

	Property level information by operating segment as of December 31, 2013, and for the years ended December 31, 2013, 2012 and 2011, is as follows:


			As of December 31,
			2013			2012
	Square feet (in thousands):
	CBD properties			20,975			21,224
	Suburban properties			16,298			40,582


	Total properties			37,273			61,806









			Year Ended December 31,
			2013			2012			2011
	Rental income:
	CBD properties		$	432,812		$	408,144		$	320,564
	Suburban properties			274,568			301,246			281,068


	Total properties		$	707,380		$	709,390		$	601,632




	Tenant reimbursements and other income:
	CBD properties		$	118,314		$	112,083		$	79,277
	Suburban properties			59,842			60,432			60,435


	Total properties		$	178,156		$	172,515		$	139,712




	NOI:
	CBD properties		$	291,544		$	280,036		$	221,737
	Suburban properties			223,123			245,265			222,199


	Total properties		$	514,667		$	525,301		$	443,936





	As of December 31, 2013, our investments in CBD properties and suburban properties, net of accumulated depreciation, excluding properties classified as held for sale, were $3,001,397 and $1,640,709, respectively, including $141,966 of CBD properties and $88,935 of suburban properties located in Australia. As of December 31, 2012, our investment in CBD properties and suburban properties, net of accumulated depreciation, excluding properties classified as held for sale, were $3,176,446 and $3,645,357, respectively, including $168,220 of CBD properties and $104,010 of suburban properties located in Australia.

The following table includes the reconciliation of NOI to net loss, the most directly comparable financial measure under GAAP reported in our consolidated financial statements. We consider NOI to be an appropriate supplemental measure to net loss because it may help both investors and management to understand the operations of our properties. We use NOI internally to evaluate individual, regional and company wide property level performance, and we believe that NOI provides useful information to investors regarding our results of operations because it reflects only those income and expense items that are incurred at the property level and may facilitate comparisons of our operating performance between periods and with other REITs. The calculation of NOI excludes certain components of net loss in order to provide results that are more closely related to our properties' results of operations. NOI does not represent cash generated by operating activities in accordance with GAAP and should not be considered as an alternative to net loss, net loss attributable to CommonWealth REIT, net loss available for CommonWealth REIT common shareholders, operating income or cash flow from operating activities, determined in accordance with GAAP, or as an indicator of our financial performance or liquidity, nor is this measure necessarily indicative of sufficient cash flow to fund all of our needs. This measure should be considered in conjunction with net loss, net loss attributable to CommonWealth REIT, net loss available for CommonWealth REIT common shareholders, operating income and cash flow from operating activities as presented in our consolidated statements of operations, consolidated statements of comprehensive (loss) income and consolidated statements of cash flows. Other REITs and real estate companies may calculate NOI differently than we do. A reconciliation of NOI to net loss for the years ended December 31, 2013, 2012 and 2011 is as follows:


		Year Ended December 31,
		2013			2012			2011
Rental income		$	707,380		$	709,390		$	601,632
Tenant reimbursements and other income			178,156			172,515			139,712
Operating expenses			(370,869	)		(356,604	)		(297,408	)


NOI		$	514,667		$	525,301		$	443,936




NOI		$	514,667		$	525,301		$	443,936
Depreciation and amortization			(218,854	)		(209,759	)		(171,662	)
General and administrative			(77,209	)		(46,057	)		(38,221	)
Loss on asset impairment			—			—			(3,036	)
Acquisition related costs			(318	)		(5,648	)		(9,731	)


Operating income			218,286			263,837			221,286
Interest and other income			1,229			1,404			1,662
Interest expense			(173,011	)		(201,840	)		(191,876	)
Loss on early extinguishment of debt			(60,052	)		(287	)		(35	)
Gain on sale of equity investment			66,293			—			—
Gain on issuance of shares by an equity investee			—			7,246			11,177


Income from continuing operations before income tax expense and equity in earnings of investees			52,745			70,360			42,214
Income tax expense			(2,634	)		(3,207	)		(1,347	)
Equity in earnings of investees			25,754			11,420			11,377


Income from continuing operations			75,865			78,573			52,244
Income from discontinued operations			15,867			9,783			22,307
Loss on asset impairment from discontinued operations			(227,122	)		(168,632	)		(7,319	)
Loss on early extinguishment of debt from discontinued operations			(1,011	)		(1,608	)		—
Net (loss) gain on sale of properties from discontinued operations			(22,162	)		2,039			42,752


(Loss) income before gain on sale of properties			(158,563	)		(79,845	)		109,984
Gain on sale of properties			1,596			—			—


Net (loss) income		$	(156,967	)	$	(79,845	)	$	109,984

Selected_Quarterly_Financial_D

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
Selected Quarterly Financial Data (Unaudited)	Dec. 31, 2013
Selected Quarterly Financial Data (Unaudited)	'
Selected Quarterly Financial Data (Unaudited)	'

	Note 16. Selected Quarterly Financial Data (Unaudited)

	The following is a summary of our unaudited quarterly results of operations for 2013 and 2012. Reclassifications have been made to the prior quarterly results to reflect properties reclassified to discontinued operations during 2013.


		2013
		First			Second			Third			Fourth
		Quarter⁽¹⁾			Quarter⁽¹⁾			Quarter⁽¹⁾			Quarter
	Total revenues	$	242,653		$	246,181		$	198,283			$198,419
	Net income (loss) available for CommonWealth REIT common shareholders		14,516			7,738			(227,466	)		(16,452	)
	Net income (loss) available for CommonWealth REIT common shareholders per share—basic and diluted		0.15			0.07			(1.92	)		(0.14	)
	Common distributions declared		0.25			0.25			0.25			0.25





		2012
		First			Second			Third			Fourth
		Quarter⁽¹⁾			Quarter⁽¹⁾			Quarter⁽¹⁾			Quarter
	Total revenues	$	209,970		$	217,346		$	222,632		$	231,957
	Net income (loss) available for CommonWealth REIT common shareholders		9,857			2,242			(122	)		(163,935	)
	Net income (loss) available for CommonWealth REIT common shareholders per share—basic and diluted		0.12			0.03			—			(1.96	)
	Common distributions declared		0.5			0.5			0.5			0.25


	-1
	Amounts previously reported have been adjusted as follows:


		2013
		First			Second			Third
		Quarter			Quarter			Quarter
	Total revenues as previously reported	$	275,048		$	274,766		$	201,741
	Total revenues from properties reclassified to discontinued operations during 2013		(32,395	)		(28,585	)		(3,458	)


	Total revenues restated	$	242,653		$	246,181		$	198,283









		2012
		First			Second			Third			Fourth
		Quarter			Quarter			Quarter			Quarter
	Total revenues as previously reported	$	243,378		$	249,797		$	255,225		$	264,692
	Total revenues from properties reclassified to discontinued operations during 2013		(33,408	)		(32,451	)		(32,593	)		(32,735	)


	Total revenues restated	$	209,970		$	217,346		$	222,632		$	231,957

SCHEDULE_II_VALUATION_AND_QUAL

SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	Dec. 31, 2013
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	'
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	'

	SCHEDULE II

	VALUATION AND QUALIFYING ACCOUNTS

	December 31, 2013

	(dollars in thousands)


	Description	Balance at		Charged to		Deductions			Balance at
		Beginning of		Costs and					End of
		Period		Expenses					Period
	Year Ended December 31, 2011:
	Allowance for doubtful accounts	$	12,550	$	2,236	$	(2,211	)	$	12,575




	Year Ended December 31, 2012:
	Allowance for doubtful accounts	$	12,575	$	504	$	(3,117	)	$	9,962




	Year Ended December 31, 2013:
	Allowance for doubtful accounts	$	9,962	$	818	$	(2,895	)	$	7,885

SCHEDULE_III_REAL_ESTATE_AND_A

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	12 Months Ended
SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	Dec. 31, 2013
SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	'
SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION	'

	SCHEDULE III

	REAL ESTATE AND ACCUMULATED DEPRECIATION

	December 31, 2013

	(dollars in thousands)


												Initial Cost to Company												Cost Amount Carried at Close of Period
																		Costs
																		Capitalized
																		Subsequent to
	Property		City		State		Property		Encumbrances⁽¹⁾			Land			Buildings and			Acquisition, Net			Impairment/			Land			Buildings and			Total⁽²⁾			Accumulated			Date		Original
							Location								Improvements						Write Downs						Improvements						Depreciation⁽³⁾			Acquired		Construction
																																						Date
	2501 20th Place South		Birmingham		AL		CBD		$	11,241		$	4,000		$	19,604		$	475		$	—		$	4,002		$	20,077		$	24,079		$	3,579		12/27/06		2001
	420 20th Street North		Birmingham		AL		CBD			—			1,740			49,565			4,213			—			1,740			53,778			55,518			3,206		7/29/11		1986
	Inverness Center		Birmingham		AL		Suburban			—			8,525			38,367			3,506			—			8,525			41,873			50,398			3,827		12/9/10		1980;1981;1982
	785 Schilinger Road South		Mobile		AL		Suburban			—			1,540			9,732			(3	)		—			1,540			9,729			11,269			1,503		10/22/07		1998
	Arizona Center		Phoenix		AZ		CBD			—			22,614			64,105			5,485			—			22,614			69,590			92,204			4,782		3/4/11		1990;1998
	4 South 84th Avenue		Tolleson		AZ		Suburban			—			1,257			9,210			696			—			1,257			9,906			11,163			2,392		12/19/03		1989
	One South Church Avenue		Tucson		AZ		CBD			—			3,261			26,357			2,728			—			3,261			29,085			32,346			8,214		2/27/02		1986
	Parkshore Plaza		Folsom		CA		Suburban			43,266			4,370			41,749			371			—			4,370			42,120			46,490			2,669		6/16/11		1999
	Leased Land		Gonzalez		CA		Suburban			—			18,941			9,060			3,822			—			18,939			12,884			31,823			1,689		8/31/10		—
	Sky Park Centre		San Diego		CA		Suburban			—			936			8,094			756			—			935			8,851			9,786			2,751		6/24/02		1986
	Sorrento Valley Business Park		San Diego		CA		Suburban			—			1,425			12,842			3,316			—			1,425			16,158			17,583			6,340		12/31/96		1984
	1921 E. Alton Avenue		Santa Ana		CA		Suburban			—			1,363			10,158			(3	)		—			1,362			10,156			11,518			2,627		11/10/03		2000
	9110 East Nichols Avenue		Centennial		CO		Suburban			—			1,708			14,616			3,960			—			1,707			18,577			20,284			5,040		11/2/01		1984
	7450 Campus Drive		Colorado Springs		CO		Suburban			—			1,250			7,982			249			—			1,250			8,231			9,481			733		4/30/10		1996
	1225 Seventeenth Street		Denver		CO		CBD			—			22,400			110,090			10,705			—			22,400			120,795			143,195			13,730		6/24/09		1982
	5073, 5075, & 5085 S. Syracuse Street		Denver		CO		Suburban			—			4,720			58,890			—			—			4,720			58,890			63,610			5,398		4/16/10		2007
	1601 Dry Creek Drive		Longmont		CO		Suburban			—			3,714			24,397			4,156			—			3,715			28,552			32,267			7,025		10/26/04		1982
	129 Worthington Ridge Road		Berlin		CT		Suburban			—			2,770			8,409			1,161			(7,088	)		1,114			4,138			5,252			451		10/24/06		1968
	97 Newberry Road		East Windsor		CT		Suburban			7,240			2,960			12,360			30			—			2,943			12,407			15,350			2,245		10/24/06		1989
	185 Asylum Street		Hartford		CT		CBD			—			15,930			60,312			820			—			15,930			61,132			77,062			2,661		3/30/12		1983
	599 Research Parkway		Meriden		CT		Suburban			—			768			6,164			1,160			—			768			7,324			8,092			1,684		7/24/03		1982
	33 Stiles Lane		North Haven		CT		Suburban			3,456			2,090			9,141			216			—			2,091			9,356			11,447			1,689		10/24/06		1970
	181 Marsh Hill Road		Orange		CT		Suburban			—			2,270			7,943			419			—			2,271			8,361			10,632			1,446		10/24/06		1993
	50 Barnes Industrial Road North		Wallingford		CT		Suburban			—			2,300			8,621			2,937			—			2,301			11,557			13,858			2,071		10/24/06		1976
	5-9 Barnes Industrial Road		Wallingford		CT		Suburban			—			740			2,552			37			—			741			2,588			3,329			475		10/24/06		1980
	860 North Main Street		Wallingford		CT		Suburban			—			680			3,144			990			—			680			4,134			4,814			813		10/24/06		1982
	One Barnes Industrial Road South		Wallingford		CT		Suburban			—			800			2,251			5			—			800			2,256			3,056			409		10/24/06		1977
	100 Northfield Drive		Windsor		CT		Suburban			—			1,376			11,212			2,911			—			1,376			14,123			15,499			4,039		8/29/03		1988
	1250 H Street, NW		Washington		DC		CBD			—			5,975			53,778			4,560			—			5,975			58,338			64,313			22,313		6/23/98		1992
	Georgetown-Green and Harris Buildings		Washington		DC		CBD			—			24,000			35,979			21			—			24,000			36,000			60,000			3,897		9/3/09		1960;1975
	802 Delaware Avenue		Wilmington		DE		CBD			—			4,409			39,681			10,320			—			4,413			49,997			54,410			20,423		7/23/98		1986
	6600 North Military Trail		Boca Raton		FL		Suburban			—			15,900			129,790			—			—			15,900			129,790			145,690			9,734		1/11/11		2008
	225 Water Street		Jacksonville		FL		CBD			38,693			1,480			43,770			3,020			—			1,480			46,790			48,270			6,280		11/24/08		1985
	The Exchange		Atlanta		GA		Suburban			—			1,576			13,134			3,195			—			1,577			16,328			17,905			3,822		9/9/2004;9/2/2005		1974;1983
	9040 Roswell Road		Atlanta		GA		Suburban			—			2,459			18,549			2,153			—			2,463			20,698			23,161			4,801		8/24/04		1985
	Executive Park		Atlanta		GA		Suburban			—			13,729			78,032			5,567			(34,109	)		13,727			49,492			63,219			12,434		7/16/2004;7/26/2007		1972
	3920 Arkwright Road		Macon		GA		Suburban			11,976			2,674			19,311			2,401			—			2,675			21,711			24,386			4,178		4/28/06		1988
	1775 West Oak Commons Court		Marietta		GA		Suburban			—			2,190			6,586			985			—			2,190			7,571			9,761			1,110		9/5/07		1998
	633 Ahua Street		Honolulu		HI		Suburban			—			1,256			3			18,047			—			1,256			18,050			19,306			2,945		12/5/03		2006
	905 Meridian Lake Drive		Aurora		IL		Suburban			—			1,740			13,586			52			—			1,740			13,638			15,378			2,265		5/1/07		1999
	1200 Lakeside Drive		Bannockburn		IL		Suburban			—			5,846			48,568			10,422			—			5,858			58,978			64,836			10,688		12/29/05		1999
	Illinois Center		Chicago		IL		CBD			151,364			66,757			239,143			22,347			—			66,757			261,490			328,247			15,082		5/11/2011;1/9/2012		1970;1972
	600 West Chicago Avenue		Chicago		IL		CBD			273,506			34,980			315,643			1,775			—			34,989			317,409			352,398			19,213		8/10/11		1908
	8750 Bryn Mawr Avenue		Chicago		IL		Suburban			—			6,600			77,764			4,292			—			6,600			82,056			88,656			6,652		10/28/10		1985
	1955 West Field Court		Lake Forest		IL		Suburban			—			1,258			9,630			2,990			—			1,261			12,617			13,878			2,495		12/14/05		2001
	101-115 W. Washington Street		Indianapolis		IN		CBD			—			7,495			60,465			20,429			—			7,496			80,893			88,389			18,710		5/10/05		1977
111 Monument Circle		Indianapolis		IN		CBD			120,885			9,670			158,085			1,577			—			9,670			159,662			169,332			4,617		10/22/12		1959;1990
5015 S. Water Circle		Wichita		KS		Suburban			—			2,720			2,029			1,124			—			2,719			3,154			5,873			570		4/2/07		1995
701 Poydras Street		New Orleans		LA		CBD			—			9,100			78,540			4,908			—			9,100			83,448			92,548			4,892		8/29/11		1972
109 Brookline Avenue		Boston		MA		CBD			—			3,168			30,397			13,591			—			3,168			43,988			47,156			18,354		9/28/95		1915
Cabot Business Park Land		Mansfield		MA		Suburban			—			1,033			—			—			—			1,033			—			1,033			—		8/1/03		—
2300 Crown Colony Drive		Quincy		MA		Suburban			—			774			5,815			1,529			—			779			7,339			8,118			2,073		2/24/04		1999
340 Thompson Road		Webster		MA		Suburban			—			315			2,834			39			—			315			2,873			3,188			1,196		5/15/97		1995
100 South Charles Street		Baltimore		MD		CBD			—			—			12,430			3,840			—			—			16,270			16,270			6,069		11/18/97		1988
111 Market Place		Baltimore		MD		CBD			—			6,328			54,645			14,343			—			6,328			68,988			75,316			19,409		1/28/03		1990
25 S. Charles Street		Baltimore		MD		CBD			—			2,830			22,996			12,672			—			2,830			35,668			38,498			9,839		7/16/04		1972
820 W. Diamond		Gaithersburg		MD		Suburban			—			4,381			18,798			9,959			—			4,461			28,677			33,138			9,245		3/31/97		1995
6710 Oxon Hill		Oxon Hill		MD		Suburban			—			3,181			13,653			2,845			—			3,131			16,548			19,679			6,668		3/31/97		1992
Danac Stiles Business Park		Rockville		MD		Suburban			—			7,638			62,572			5,077			—			7,639			67,648			75,287			14,982		7/20/04		2002
East Eisenhower Parkway		Ann Arbor		MI		Suburban			—			6,760			46,988			982			—			6,760			47,970			54,730			4,252		6/15/10		1975;2006
2250 Pilot Knob Road		Mendota Heights		MN		Suburban			—			533			4,795			1,103			—			533			5,898			6,431			2,179		3/19/98		1995
9800 Shelard Parkway		Plymouth		MN		Suburban			—			563			5,064			1,022			—			563			6,086			6,649			2,367		8/3/99		1987
Rosedale Corporate Plaza		Roseville		MN		Suburban			—			1,860			16,750			8,949			—			1,859			25,700			27,559			7,541		12/1/99		1987
411 Farwell Avenue		South St. Paul		MN		Suburban			—			1,303			10,451			3,949			—			1,304			14,399			15,703			2,613		6/2/04		1970
6200 Glenn Carlson Drive		St. Cloud		MN		Suburban			7,987			1,950			13,803			—			—			1,950			13,803			15,753			1,467		10/15/09		1999
1000 Shelard Parkway		St. Louis Park		MN		Suburban			—			695			6,254			2,004			—			695			8,258			8,953			3,018		8/3/99		1986
525 Park Street		St. Paul		MN		CBD			—			696			6,263			1,669			—			695			7,933			8,628			3,150		8/3/99		1987
1900 Meyer Drury Drive		Arnold		MO		Suburban			—			834			7,302			475			—			838			7,773			8,611			1,830		2/11/04		1999
4700 Belleview Avenue		Kansas City		MO		Suburban			—			1,165			3,097			2,110			—			1,165			5,207			6,372			601		7/17/08		1986
131-165 West Ninth Street		N. Kansas City		MO		Suburban			—			494			959			300			—			494			1,259			1,753			165		7/17/08		1970
12655 Olive Boulevard		St. Louis		MO		Suburban			—			4,800			8,020			1,690			—			4,801			9,709			14,510			1,633		10/5/06		1988
1285 Fern Ridge Parkway		St. Louis		MO		Suburban			—			903			7,602			1,110			—			903			8,712			9,615			2,162		11/7/03		1998
300 North Greene Street		Greensboro		NC		CBD			—			2,070			37,073			1,184			—			2,070			38,257			40,327			3,228		9/14/10		1989
111 River Street		Hoboken		NJ		CBD			—			—			134,199			201			—			—			134,400			134,400			14,836		8/11/09		2002
5 Paragon Drive		Montvale		NJ		Suburban			—			3,650			13,725			309			—			3,650			14,034			17,684			1,010		2/11/11		1984
One Park Square		Albuquerque		NM		CBD			—			2,582			21,532			4,668			—			2,582			26,200			28,782			7,492		2/12/02		1985;1987
North Point Office Complex		Cleveland		OH		CBD			—			12,000			94,448			14,954			—			12,000			109,402			121,402			15,380		2/12/08		1985;1989;1990
401 Vine Street		Delmont		PA		Suburban			—			1,575			5,542			—			—			1,575			5,542			7,117			853		10/22/07		1999
515 Pennsylvania Avenue		Fort Washington		PA		Suburban			—			1,872			8,816			4,291			—			1,872			13,107			14,979			4,331		9/22/97		1958
443 Gulph Road		King of Prussia		PA		Suburban			—			634			3,251			1,070			—			634			4,321			4,955			1,932		9/22/97		1966
4350 Northern Pike		Monroeville		PA		Suburban			—			6,558			51,775			16,895			—			6,564			68,664			75,228			13,106		9/16/04		1971
Cherrington Corporate Center		Moon Township		PA		Suburban			—			11,369			39,892			18,008			—			12,192			57,077			69,269			17,405		9/14/1998;8/23/1999		1987;1988;1989;
																																					1990;1991;1992;
																																					1994
1500 Market Street		Philadelphia		PA		CBD			—			18,758			167,487			89,351			—			18,758			256,838			275,596			63,340		10/10/02		1974
1525 Locust Street		Philadelphia		PA		CBD			—			931			8,377			1,605			—			930			9,983			10,913			3,341		6/11/99		1987
1600 Market Street		Philadelphia		PA		CBD			—			3,462			111,946			24,590			—			3,462			136,536			139,998			55,731		3/30/98		1983
1735 Market Street		Philadelphia		PA		CBD			173,247			24,753			222,775			49,206			—			24,747			271,987			296,734			104,277		6/30/98		1990
Foster Plaza		Pittsburgh		PA		Suburban			—			6,168			51,588			13,209			—			6,169			64,796			70,965			13,813		9/16/05		1987;1990;1994;
Foster Plaza		Pittsburgh		PA		Suburban			—			6,168			51,588			13,209			—			6,169			64,796			70,965			13,813		9/16/05		1995;1996
128 Crews Drive		Columbia		SC		Suburban			—			2,420			4,017			1,321			(4,012	)		1,024			2,722			3,746			279		4/2/07		1968
1320 Main Street		Columbia		SC		CBD			41,480			1,660			53,058			25			—			1,660			53,083			54,743			1,661		9/18/12		2004
111 Southchase Boulevard		Fountain Inn		SC		Suburban			—			520			6,822			967			—			520			7,789			8,309			1,195		5/23/07		1987
1043 Global Avenue		Graniteville		SC		Suburban			—			720			15,552			358			—			720			15,910			16,630			2,603		4/2/07		1998
633 Frazier Drive		Franklin		TN		Suburban			—			5,800			13,190			(10	)		—			5,800			13,180			18,980			2,052		10/22/07		1999
775 Ridge Lake Boulevard		Memphis		TN		CBD			—			2,113			18,201			499			—			2,114			18,699			20,813			4,539		4/28/04		2000
1601 Rio Grande Street		Austin		TX		CBD			—			688			6,192			1,160			—			697			7,343			8,040			2,637		6/3/99		1985
206 East 9th Street		Austin		TX		CBD			30,169			7,900			38,533			1,201			—			7,900			39,734			47,634			1,531		5/31/12		1984
4515 Seton Center Parkway		Austin		TX		Suburban			—			2,038			18,338			2,779			—			2,037			21,118			23,155			7,785		10/8/99		1997
4516 Seton Center Parkway		Austin		TX		Suburban			—			2,028			18,251			2,799			—			2,027			21,051			23,078			7,779		10/8/99		1985
7800 Shoal Creek Boulevard		Austin		TX		Suburban			—			1,731			14,921			3,736			—			1,731			18,657			20,388			6,279		6/30/99		1974
812 San Antonio Street		Austin		TX		CBD			—			626			5,636			2,207			—			621			7,848			8,469			2,535		8/18/99		1987
8701 N Mopac		Austin		TX		Suburban			—			1,574			14,168			2,651			—			1,573			16,820			18,393			5,759		8/3/99		1982
Bridgepoint Parkway		Austin		TX		Suburban			—			7,784			70,526			9,302			—			7,784			79,828			87,612			32,105		12/5/97		1986;1996;1997
Lakewood on the Park		Austin		TX		Suburban			—			3,548			31,936			1,512			—			3,548			33,448			36,996			12,603		10/20/98		1998
Research Park		Austin		TX		Suburban			—			15,859			60,175			14,520			—			18,411			72,143			90,554			24,124		10/7/98		1968;1998;2001
9840 Gateway Boulevard North		El Paso		TX		Suburban			—			1,700			9,736			(4	)		—			1,700			9,732			11,432			1,509		10/22/07		1999
3003 South Expressway 281		Hidalgo		TX		Suburban			—			1,480			15,533			(9	)		—			1,480			15,524			17,004			2,417		10/22/07		1999
3330 N Washington Boulevard		Arlington		VA		Suburban			—			810			7,289			616			—			811			7,904			8,715			2,898		8/26/98		1987
6160 Kempsville Circle		Norfolk		VA		Suburban			—			1,273			11,083			4,226			—			1,273			15,309			16,582			5,221		10/25/02		1987
Thunderbolt Place		Chantilly		VA		Suburban			—			1,374			12,369			941			—			1,375			13,309			14,684			4,919		9/29/99		1988
448 Viking Drive		Virginia Beach		VA		Suburban			—			682			5,431			1,429			—			686			6,856			7,542			1,425		6/4/04		1991
333 108th Avenue NE		Bellevue		WA		CBD			—			14,400			136,412			1,666			—			14,400			138,078			152,478			14,798		11/12/09		2008
600 108th Avenue NE		Bellevue		WA		CBD			—			3,555			30,244			8,953			—			3,555			39,197			42,752			8,637		7/16/04		1980
1331 North Center Parkway		Kennewick		WA		Suburban			—			1,850			7,339			(2	)		—			1,850			7,337			9,187			1,139		10/22/07		1999
100 East Wisconsin Avenue		Milwaukee		WI		CBD			—			3,150			72,113			4,592			—			3,150			76,705			79,855			6,676		8/11/10		1989
111 East Kilbourn Avenue		Milwaukee		WI		CBD			—			2,400			47,562			4,897			—			2,400			52,459			54,859			7,481		6/12/08		1988
Australia:
7 Modal Crescent		Canning Vale		Australia		Suburban			—			9,806			3,925			641			—			8,915			5,457			14,372			358		10/7/10		2001
71-93 Whiteside Road		Clayton		Australia		Suburban			—			9,757			8,495			(1,658	)		—			8,870			7,724			16,594			624		10/7/10		1965
9-13 Titanium Court		Crestmead		Australia		Suburban			—			3,400			3,185			(598	)		—			3,091			2,896			5,987			234		10/7/10		2005
16 Rodborough Road		Frenchs Forest		Australia		Suburban			—			7,355			9,498			(1,069	)		—			6,686			9,098			15,784			710		10/7/10		1987
22 Rodborough Road		Frenchs Forest		Australia		Suburban			—			2,452			3,923			320			—			2,229			4,466			6,695			343		10/7/10		1997
127-161 Cherry Lane		Laverton North		Australia		Suburban			—			4,266			5,220			(862	)		—			3,878			4,746			8,624			384		10/7/10		1965
310-314 Invermay Road		Mowbray		Australia		Suburban			—			431			535			(87	)		—			392			487			879			39		10/7/10		1963
253-293 George Town Road		Rocherlea		Australia		Suburban			—			2,108			1,331			(312	)		—			1,917			1,210			3,127			98		10/7/10		1963
310-320 Pitt Street		Sydney		Australia		CBD			—			63,271			104,588			(18,524	)		—			56,610			92,725			149,335			7,370		12/21/10		1989
44-46 Mandarin Street		Villawood		Australia		Suburban			—			6,374			8,179			(556	)		—			5,795			8,202			13,997			613		10/7/10		1980
19 Leadership Way		Wangara		Australia		Suburban			—			4,217			2,685			(421	)		—			3,833			2,648			6,481			203		10/7/10		2000


								$	914,510		$	709,968		$	4,319,098		$	553,308		$	(45,209	)	$	699,135		$	4,838,030		$	5,537,165		$	895,059





Analysis of the carrying amount of real estate properties and accumulated depreciation:


		Real Estate			Accumulated
		Properties			Depreciation
Balance at January 1, 2011		$	6,357,258		$	850,261
Additions⁽⁴⁾			1,074,010			166,371
Properties reclassified to continuing operations			42,228			3,083
Disposals			(229,264	)		(85,545	)


Balance at December 31, 2011			7,244,232			934,170
Additions⁽⁴⁾			1,041,655			188,220
Loss on asset impairment			(242,497	)		(73,865	)
Properties reclassified to continuing operations			(174,562	)		(10,521	)
Disposals			(39,419	)		(30,398	)


Balance at December 31, 2012			7,829,409			1,007,606
Additions⁽⁴⁾			231,485			176,777
Loss on asset impairment			(384,141	)		(185,795	)
Deconsolidation of SIR			(1,446,781	)		(56,023	)
Properties reclassified to discontinued operations			(552,024	)		(15,471	)
Disposals			(140,783	)		(32,035	)


Balance at December 31, 2013		$	5,537,165		$	895,059






-1
Includes net unamortized premiums and discounts.

-2
Excludes value of real estate intangibles. Aggregate cost for federal income tax purposes is approximately $5,642,335.

-3
Depreciation is calculated using the straight line method over estimated useful lives of up to 40 years for buildings and improvements and up to 12 years for personal property.

-4
Includes adjustments to real estate properties additions of ($40,020), $4,986 and ($333), and adjustments to accumulated depreciation additions of ($1,528), $97 and ($73), related to changes in foreign currency exchange rates during 2013, 2012 and 2011, respectively.

SCHEDULE_IV_MORTGAGE_LOANS_ON_

SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE	12 Months Ended
SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE	Dec. 31, 2013
SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE	'
SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE	'

	SCHEDULE IV

	MORTGAGE LOANS ON REAL ESTATE

	December 31, 2013

	(dollars in thousands)


	Location	Interest	Final		Periodic Payment Terms	Face			Carrying		Principal Amount of
		Rate	Maturity Date			Amount of			Amount		Loans Subject to
						Mortgage⁽¹⁾			of Mortgage		Delinquent Principal
											or Interest
	Salina, NY	6.00%		4/30/19	Interest payable monthly in arrears.	$	419			419	$	—
	Salina, NY	6.00%		4/30/19	$419 due at maturity.	$	419			419	$	—
	Dearborn, MI	6.00%		1/24/23	Interest payable monthly in arrears.		7,688			7,688		—
	Dearborn, MI	6.00%		1/24/23	$7,688 due at maturity.		7,688			7,688		—


						$	8,107		$	8,107	$	—




	Reconciliation of the carrying amount of mortgage loans at the beginning of the period:
	Balance at January 1, 2011					$	8,183
	Collections of principal						(8,183	)


	Balance at December 31, 2011						—
	New mortgage loans						1,419


	Balance at December 31, 2012						1,419
	New mortgage loans						7,688
	Collections of principal						(1,000	)


	Balance at December 31, 2013					$	8,107






	-1
	Also represents cost for federal income tax purposes.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2013
Summary of Significant Accounting Policies	'
Basis of Presentation	'

	Basis of Presentation. The consolidated financial statements include our investments in 100% owned subsidiaries and majority owned subsidiaries that are controlled by us. References to we, us, our and the Company, refer to CommonWealth REIT and its consolidated subsidiaries as of December 31, 2013, unless the context indicates otherwise. The portion of a consolidated subsidiary that is not controlled by us, or the noncontrolling interest, is presented as a separate component of equity in our consolidated balance sheets. In addition, net income attributable to the noncontrolling interest is presented separately in our consolidated statements of operations. All intercompany transactions and balances have been eliminated.

	We account for our investments in 50% or less owned companies, including our investments in SIR (beginning on July 2, 2013 when SIR ceased to be our consolidated subsidiary), GOV (until March 15, 2013, when we sold all of our GOV common shares) and Affiliates Insurance Company, or AIC, over which we can exercise influence, but do not control, using the equity method of accounting. Significant influence is present through common representation on the boards of trustees or directors of us and each of SIR, GOV and AIC. Our two Managing Trustees are also managing trustees of SIR and GOV, and owners of Reit Management & Research LLC, or RMR, which is the business and property manager of us, SIR, GOV and AIC, and a majority of our Trustees are directors of AIC. We use the income statement method to account for issuance of common shares of beneficial interest by SIR and GOV (until March 15, 2013, when we sold all of our GOV common shares), and shares of common stock by AIC. Under this method, gains and losses reflecting changes in the value of our investments at the date of issuance of additional common shares by SIR and GOV, or common stock by AIC, are recognized in our income statement.

Real Estate Properties	'

	Real Estate Properties. We record real estate properties at cost. We depreciate real estate investments on a straight line basis over estimated useful lives of up to 40 years for buildings and improvements, and up to 12 years for personal property.

	We allocate the consideration paid for our properties among land, buildings and improvements and, for properties that qualify as acquired businesses under the Business Combinations Topic of the FASB Accounting Standards Codification^TM, or the Codification, to identified intangible assets and liabilities, consisting of the value of above market and below market leases, the value of acquired in place leases and the value of tenant relationships. Purchase price allocations and the determination of useful lives are based on our estimates and, under some circumstances, studies from independent real estate appraisal firms to provide market information and evaluations that are relevant to our purchase price allocations and determinations of useful lives; however, we are ultimately responsible for the purchase price allocations and determination of useful lives.

	We allocate the consideration to land, buildings and improvements based on a determination of the fair values of these assets assuming the property is vacant. We determine the fair value of a property using methods that we believe are similar to those used by independent appraisers. Purchase price allocations to above market and below market leases are based on the estimated present value (using an interest rate which reflects our assessment of the risks associated with the leases acquired) of the difference between (1) the contractual amounts to be paid pursuant to the acquired in place leases and (2) our estimate of fair market lease rates for the corresponding leases, measured over a period equal to the remaining non-cancelable terms of the respective leases. Purchase price allocations to acquired in place leases and tenant relationships are determined as the excess of (1) the purchase price paid for a property after adjusting existing in place leases to estimated market rental rates over (2) the estimated fair value of the property as if vacant. We aggregate this value between acquired in place lease values and tenant relationships based on our evaluation of the specific characteristics of each tenant's lease; however, the value of tenant relationships has not been separated from acquired in place lease value for our properties because we believe such value and related amortization expense is immaterial for acquisitions reflected in our historical financial statements. We consider certain factors in performing these analyses including estimates of carrying costs during the expected lease up periods, including real estate taxes, insurance and other operating income and expenses and costs to execute similar leases in current market conditions, such as leasing commissions, legal and other related costs. If we believe the value of tenant relationships is material in the future, those amounts will be separately allocated and amortized over the estimated lives of the relationships. We recognize the excess, if any, of the consideration paid over amounts allocated to land, buildings and improvements and identified intangible assets and liabilities as goodwill and we recognize gains if amounts allocated exceed the consideration paid.

	We amortize capitalized above market lease values (presented in our consolidated balance sheets as acquired real estate leases) as a reduction to rental income over the remaining terms of the respective leases. We amortize capitalized below market lease values (presented in our consolidated balance sheets as assumed real estate lease obligations) as an increase to rental income over the remaining terms of the respective leases. Such amortization resulted in net reductions to rental income of $10,158, $10,274 and $8,766 during the years ended December 31, 2013, 2012 and 2011, respectively, and net increases to income from discontinued operations of $623, $312 and $286, for the years ended December 31, 2013, 2012 and 2011, respectively. We amortize the value of acquired in place leases exclusive of the value of above market and below market acquired in place leases to expense over the remaining terms of the respective leases. The amount of such amortization included in depreciation and amortization totaled $47,586, $45,475 and $32,907 during the years ended December 31, 2013, 2012 and 2011, respectively. The amount of such amortization included in income from discontinued operations totaled $2,157, $4,740 and $7,058 during the years ended December 31, 2013, 2012 and 2011, respectively. If a lease is terminated prior to its stated expiration, the unamortized amount relating to that lease is written off.

	Capitalized above market lease values for properties held and used in operations were $127,944 and $190,402 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $48,841 and $56,374, respectively, as of those same respective dates. Capitalized above market lease values for properties held for sale was $2,047 and $1,191 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $0 and $1,060, respectively, as of those same respective dates. Capitalized below market lease values for properties held and used in operations were $56,815 and $106,643 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $22,880 and $37,339, respectively, as of those same respective dates. Capitalized below market lease values for properties held for sale was $4,996 and $92 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $2,926 and $71, respectively, as of those same respective dates. The value of acquired in place leases, exclusive of the value of above and below market in place leases for properties held and used in operations were $282,754 and $393,068 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $106,045 and $99,340, respectively, as of those same respective dates. The value of acquired in place leases, exclusive of the value of above and below market in place leases for properties held for sale was $9,351 and $2,297 as of December 31, 2013 and 2012, respectively, net of accumulated amortization of $4,461 and $1,975, respectively, as of those same respective dates. Future amortization of net intangible lease assets and liabilities to be recognized by us during the current terms of our leases as of December 31, 2013 are approximately $46,204 in 2014, $39,690 in 2015, $32,172 in 2016, $24,996 in 2017, $20,876 in 2018 and $57,939 thereafter.

	We recognize impairment losses on investments when indicators of impairment are present and the estimated undiscounted cash flow from our investments is less than the carrying amount of such investments. Impairment indicators may include declining tenant occupancy, lack of progress releasing vacant space, tenant bankruptcies, low long term prospects for improvement in property performance, weak or declining tenant profitability, cash flow or liquidity, our decision to dispose of an asset before the end of its estimated useful life and legislative, market or industry changes that could permanently reduce the value of a property. We review our properties for impairment quarterly, or whenever events or changes in circumstances indicate that their carrying amounts may not be recoverable. If indicators of impairment are present, we evaluate the carrying value of the related property by comparing it to the expected future undiscounted cash flows to be generated from that property. If the sum of these expected future cash flows is less than the carrying value, we reduce the net carrying value of the property to its estimated fair value. The determination of undiscounted cash flow includes consideration of many factors including income to be earned from the investment, holding costs (exclusive of interest), estimated selling prices, and prevailing economic and market conditions.

	When we classify properties as held for sale, we discontinue the recording of depreciation expense and estimate their fair value less costs to sell. If we determine that the carrying value for these properties exceed their estimated fair value less costs to sell, we record a loss on asset impairment. During the year ended December 31, 2013, we recorded a loss on asset impairment totaling $204,036 to reduce the carrying value of 39 properties (93 buildings) classified as held for sale to their estimated fair value less costs to sell (see Note 14). In addition, we recorded losses on asset impairment for properties sold during 2013 totaling $23,086.

	Certain of our real estate assets contain hazardous substances, including asbestos. We believe any asbestos in our buildings is contained in accordance with current regulations, and we have no current plans to remove any such asbestos. If we remove the asbestos or renovate or demolish these properties, certain environmental regulations govern the manner in which the asbestos must be handled and removed. We do not believe that there are other environmental conditions at any of our properties that have a material adverse effect on us. However, no assurances can be given that such conditions are not present in our properties or that other costs we incur to remediate contamination will not have a material adverse effect on our business or financial condition. As of December 31, 2013 and 2012, accrued environmental remediation costs by us and SIR (as of December 31, 2012 only, when SIR was our consolidated subsidiary) totaling $418 and $10,798, respectively, were included in accounts payable and accrued expenses in our consolidated balance sheets.

Cash and Cash Equivalents	'
Cash and Cash Equivalents	Cash and Cash Equivalents. We carry cash and short term investments with original maturities of three months or less at the date of purchase at cost plus accrued interest.
Restricted Cash	'
Restricted Cash	Restricted Cash. Restricted cash consists of amounts escrowed for future real estate taxes, insurance, leasing costs, capital expenditures and debt service, as required by some of our mortgage debts, as well as security deposits paid to us by some of our tenants.
Other Assets, Net	'
Other Assets, Net	Other Assets, Net. Other assets consist principally of deferred financing fees, deferred leasing costs, capitalized lease incentives and prepaid property operating expenses. Deferred financing fees include issuance costs related to borrowings and are capitalized and amortized over the terms of the respective loans. At December 31, 2013 and 2012, deferred financing fees totaled $45,985 and $58,783, respectively, and accumulated amortization for deferred financing fees totaled $21,455 and $21,623, respectively, as of those same respective dates. At December 31, 2013, deferred financing fees for properties held for sale totaled $272, and accumulated amortization for deferred financing fees for properties held for sale totaled $132, as of that same respective date. Deferred leasing costs include brokerage, legal and other fees associated with the successful negotiation of leases and are amortized on a straight line basis over the terms of the respective leases. Deferred leasing costs for properties held and used in operations totaled $146,996 and $151,115 at December 31, 2013 and 2012, respectively, and accumulated amortization for deferred leasing costs for properties held and used in operations totaled $46,228 and $49,652, respectively, as of those same respective dates. Deferred leasing costs for properties held for sale totaled $13,769 and $4,771 at December 31, 2013 and 2012, respectively, and accumulated amortization for deferred leasing costs for properties held for sale totaled $987 and $2,110, respectively, as of those same respective dates. Capitalized lease incentives are amortized on a straight line basis against rental income over the terms of the respective leases. Capitalized lease incentives for properties held and used in operations totaled $20,651 and $20,491 at December 31, 2013 and 2012, respectively, and accumulated amortization for capitalized lease incentives for properties held and used in operations totaled $5,392 and $3,828, respectively, as of those same respective dates. Capitalized lease incentives for properties held for sale totaled $590 as of December 31, 2013, and accumulated amortization for capitalized lease incentives for properties held for sale totaled $40, as of that same respective date. Future amortization of deferred financing fees and leasing costs to be recognized by us during the current terms of our loans and leases as of December 31, 2013 are approximately $22,693 in 2014, $21,041 in 2015, $17,274 in 2016, $14,233 in 2017, $12,230 in 2018 and $37,827 thereafter. Future amortization of capitalized lease incentives to be recognized by us during the current terms of our leases as of December 31, 2013 are approximately $2,256 in 2014, $2,236 in 2015, $2,225 in 2016, $2,152 in 2017, $2,069 in 2018 and $4,321 thereafter.
Accounting Policy for Derivative Instruments	'

	Accounting Policy for Derivative Instruments. The Derivatives and Hedging Topic of the Codification requires companies to recognize all their derivative instruments as either assets or liabilities in the statement of financial position at fair value. The accounting for changes in the fair value of a derivative instrument depends on whether such instrument has been designated and qualifies as part of a hedging relationship and, further, on the type of hedging relationship. For those derivative instruments that are designated and qualify as hedging instruments, we must designate the hedging instrument, based upon the exposure being hedged, as a fair value hedge, cash flow hedge or a hedge of a net investment in a foreign operation. In December 2009, we entered into interest rate swap agreements that qualify as cash flow hedges. As of December 31, 2013 and 2012, the fair value of our derivative instrument of $11,706 and $16,624, respectively, was included in accounts payable and accrued expenses and cumulative other comprehensive (loss) income in our consolidated balance sheets.

	We are exposed to certain risks relating to our ongoing business operations. The primary risk managed by using derivative instruments is interest rate risk. Interest rate swaps are entered into to manage interest rate risk associated with our floating rate borrowings. We designate certain interest rate swaps as cash flow hedges of floating rate borrowings.

Revenue Recognition	'
Revenue Recognition	Revenue Recognition. Rental income from operating leases, which includes rent concessions (including free rent and other lease incentives) and scheduled increases in rental rates during the lease term, is recognized on a straight line basis over the life of the lease agreements. We defer the recognition of contingent rental income, such as percentage rents, until the specific targets that trigger the contingent rental income are achieved. Tenant reimbursements and other income includes property level operating expenses reimbursed by our tenants, as well as other incidental revenues.
Allowance for Doubtful Accounts	'
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts. We maintain an allowance for doubtful accounts for estimated losses resulting from the inability or unwillingness of certain tenants to make payments required under their leases. The computation of the allowance is based on the tenants' payment histories and current credit profiles, as well as other considerations.
Earnings Per Common Share	'

	Earnings Per Common Share. Earnings per common share, or EPS, is computed using the weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if our series D convertible preferred shares were converted into our common shares, where such conversion would result in a lower EPS amount. The effect of our series D convertible preferred shares on income from continuing operations and net income available for common shareholders is anti-dilutive for all periods presented.

	As discussed in Note 3, if the consent solicitation by Related Fund Management, LLC and Corvex Management LP, or together, Related/Corvex, is successful in removing our entire Board of Trustees, such removal would constitute a fundamental change under our 6.5% series D cumulative convertible preferred shares giving holders of such shares the option to convert these shares into common shares at a ratio based on 98% of the average closing market price for a period before such removal is effective unless we repurchase these shares for their par value plus accrued and unpaid distributions. The issuance of such a large number of common shares as a result of the exercise of this conversion right after a fundamental change may have a dilutive effect on income from continuing operations attributable to CommonWealth REIT common shareholders per share for future periods.

Reclassifications	'
Reclassifications	Reclassifications. Reclassifications have been made to the prior years' financial statements and notes to conform to the current year's presentation.
Income Taxes	'

	Income Taxes. We are a REIT under the Internal Revenue Code of 1986, as amended, and are generally not subject to federal and state income taxes provided we distribute our taxable income to our shareholders and meet other requirements for qualifying as a real estate investment trust. However, we are subject to certain state, local and Australian taxes without regard to our REIT status.

	The Income Taxes Topic of the Codification prescribes how we should recognize, measure and present in our financial statements uncertain tax positions that have been taken or are expected to be taken in a tax return. Deferred tax assets are recognized to the extent that it is "more likely than not" that a particular tax position will be sustained upon examination or audit. To the extent the "more likely than not" standard has been satisfied, the benefit associated with a tax position is measured as the largest amount that has a greater than 50% likelihood of being realized upon settlement. We classify interest and penalties related to uncertain tax positions, if any, in our financial statements as a component of general and administrative expense.

Use of Estimates	'
Use of Estimates	Use of Estimates. Preparation of these financial statements in conformity with U.S. generally accepted accounting principles, or GAAP, requires us to make estimates and assumptions that may affect the amounts reported in these financial statements and related notes. The actual results could differ from these estimates.
Foreign Operations	'
Foreign Operations	Foreign Operations. The U.S. dollar is the functional currency for our consolidated subsidiaries operating in the United States. The functional currency for our consolidated subsidiaries in countries other than the United States is the principal currency in which the entity's assets, liabilities, income and expenses are denominated. The functional currency of our consolidated subsidiary that operates in Australia is the Australian dollar. We translate our Australian subsidiary's financial statements into U.S. dollars when we consolidate that subsidiary's financial statements on a quarterly basis. Generally, we translate assets and liabilities at the exchange rate in effect as of the balance sheet date. The resulting translation adjustments are included in cumulative other comprehensive (loss) income in our consolidated balance sheets. We translate income statement accounts using the average exchange rate for the period and income statement accounts that include significant non-recurring transactions at the rate in effect as of the date of the transaction. We are subject to foreign currency risk due to potential fluctuations in exchange rates between Australian and U.S. currencies. A significant change in the value of Australian currency compared to U.S. currency would have an effect on future reported results of operations and financial position. We do not currently borrow in Australian dollars or enter currency derivative contracts to mitigate foreign currency risk. As of December 31, 2013 and 2012, cumulative foreign currency translation adjustments were ($26,647) and $17,071, respectively.
New Accounting Pronouncements	'
New Accounting Pronouncements	New Accounting Pronouncements. Effective January 2013, we adopted Financial Accounting Standards Board, or FASB, Accounting Standards Update No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. This update is the culmination of the FASB's deliberation on reporting reclassification adjustments from accumulated other comprehensive income, or AOCI. This standard does not change the current requirements for reporting net income or other comprehensive income. However, it requires disclosure of amounts reclassified out of AOCI in their entirety, by component, on the face of the statement of operations or in the notes thereto. Amounts that are not required to be reclassified in their entirety to net income must be cross referenced to other disclosures that provide additional detail. This update was effective prospectively for interim and annual reporting periods beginning after December 15, 2012. The implementation of this update did not cause any material changes to the presentation of our consolidated financial statements.

Real_Estate_Properties_Tables

Real Estate Properties (Tables)	12 Months Ended
Real Estate Properties (Tables)	Dec. 31, 2013
Real Estate Properties	'
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	'



	Balance Sheets:


		December 31,
		2013			2012
	Real estate properties	$	536,552		$	164,041
	Acquired real estate leases		6,937			453
	Rents receivable		14,180			2,791
	Other assets, net		15,862			4,547


	Properties held for sale	$	573,531		$	171,832




	Mortgage notes payable, net	$	20,018		$	—
	Assumed real estate lease obligations		2,070			21
	Rent collected in advance		4,043			854
	Security deposits		2,603			1,464


	Liabilities related to properties held for sale	$	28,734		$	2,339





	Income Statements:


		Year Ended December 31,
		2013			2012			2011
	Rental income	$	110,955		$	134,962		$	163,159
	Tenant reimbursements and other income		18,453			22,128			27,905


	Total revenues		129,408			157,090			191,064


	Operating expenses		76,203			87,774			104,449
	Depreciation and amortization		28,098			48,533			51,493
	General and administrative		7,563			8,675			9,254
	Acquisition related costs		—			—			471


	Total expenses		111,864			144,982			165,667


	Operating income		17,544			12,108			25,397
	Interest and other income		65			79			58
	Interest expense		(1,742	)		(2,404	)		(3,148	)


	Income from discontinued operations	$	15,867		$	9,783		$	22,307




Schedule of future minimum lease payments receivable	'

	The future minimum lease payments scheduled to be received by us during the current terms of our leases as of December 31, 2013 are as follows:


	2014	$	589,603
	2015		564,468
	2016		501,714
	2017		441,682
	2018		391,015
	Thereafter		1,350,719


		$	3,839,201




Schedule of future minimum lease payments	'

	The future minimum lease payments scheduled to be paid by us during the current terms of this ground lease under which we are the lessee, as of December 31, 2013, are as follows:


	2014	$	1,477
	2015		1,477
	2016		1,477
	2017		1,477
	2018		1,483
	Thereafter		131,496


		$	138,887

Investment_in_Direct_Financing1

Investment in Direct Financing Lease (Tables)	12 Months Ended
Investment in Direct Financing Lease (Tables)	Dec. 31, 2013
Investment in Direct Financing Lease	'
Carrying amount of net investment in direct financing lease	'






		December 31,
		2013			2012
	Total minimum lease payments receivable	$	22,986		$	31,084
	Estimated unguaranteed residual value of leased asset		4,951			4,951
	Unearned income		(8,174	)		(9,302	)


	Net investment in direct financing lease	$	19,763		$	26,733




Schedule of future minimum rentals receivable on direct financing lease	'

	Our direct financing lease has an expiration date in 2045. Future minimum rentals receivable on this direct financing lease as of December 31, 2013 are as follows:


	2014	$	8,098
	2015		8,098
	2016		226
	2017		226
	2018		226
	Thereafter		6,112


		$	22,986

Equity_Investments_Tables

Equity Investments (Tables)	12 Months Ended
Equity Investments (Tables)	Dec. 31, 2013
Equity Investments	'
Schedule of equity investments	'






		Ownership Percentage						Equity Investments				Equity in Earnings
		December 31,						December 31,				Year Ended December 31,
		2013			2012			2013		2012		2013		2012		2011
	SIR		44.2	%		56.00%	-1	$	512,078	$	—	$	21,153	$	—	$	—
	GOV		0	%		18.20%			—		173,452		4,111		10,836		11,238
	AIC		12.5	%		25.00%			5,913		11,259		490		584		139


								$	517,991	$	184,711	$	25,754	$	11,420	$	11,377






	-1
	SIR's financial position and results of operations were consolidated in our financial statements as of December 31, 2012, and therefore not reflected in the table above.

SIR	'
Equity Investments	'
Summary of balance sheet information of equity method investee	'






		December 31,
		2013			2012
	Real estate properties, net	$	1,579,234		$	1,249,081
	Acquired real estate leases, net		129,426			95,248
	Cash and cash equivalents		20,025			20,373
	Rents receivable, net		55,335			38,885
	Other assets, net		17,839			27,065


	Total assets	$	1,801,859		$	1,430,652




	Revolving credit facility	$	159,000		$	95,000
	Term loan		350,000			350,000
	Mortgage notes payable		27,147			27,778
	Assumed real estate lease obligations, net		26,966			20,434
	Other liabilities		40,055			37,257
	Shareholders' equity		1,198,691			900,183


	Total liabilities and shareholders' equity	$	1,801,859		$	1,430,652




Summary of income statement information of equity method investee	'






		Year Ended December 31,
		2013			2012			2011
	Rental income	$	159,011		$	105,559		$	91,775
	Tenant reimbursements and other income		29,312			17,231			16,847


	Total revenues		188,323			122,790			108,622


	Operating expenses		36,382			23,796			22,946
	Depreciation and amortization		31,091			14,860			11,205
	Acquisition related costs		2,002			2,470			—
	General and administrative		12,423			8,203			5,528


	Total expenses		81,898			49,329			39,679


	Operating income		106,425			73,461			68,943
	Interest expense		(13,763	)		(7,565	)		—


	Income before income tax expense and equity in earnings of an investee		92,662			65,896			68,943
	Income tax benefit (expense)		96			(290	)		—
	Equity in earnings of an investee		334			269			—


	Net income	$	93,092		$	65,875		$	68,943




	Weighted average common shares outstanding		44,565			27,122			—




	Net income per common share	$	2.09		$	2.43			N/A




GOV	'
Equity Investments	'
Summary of balance sheet information of equity method investee	'






		December 31,
		2012
	Real estate properties, net	$	1,311,202
	Assets of discontinued operations		47,142
	Acquired real estate leases, net		144,402
	Cash and cash equivalents		5,255
	Rents receivable, net		28,882
	Other assets, net		25,251


	Total assets	$	1,562,134




	Unsecured revolving credit facility	$	49,500
	Unsecured term loan		350,000
	Mortgage notes payable		93,127
	Liabilities of discontinued operations		298
	Assumed real estate lease obligations, net		19,129
	Other liabilities		22,629
	Shareholders' equity		1,027,451


	Total liabilities and shareholders' equity	$	1,562,134




Summary of income statement information of equity method investee	'






		Year Ended
		December 31,
		2012			2011
	Rental income	$	203,700		$	168,074


	Operating expenses		75,326			62,117
	Depreciation and amortization		49,070			37,776
	Acquisition related costs		1,614			3,504
	General and administrative		11,924			10,469


	Total expenses		137,934			113,866


	Operating income		65,766			54,208
	Interest and other income		29			104
	Interest expense		(16,892	)		(12,057	)


	Income from continuing operations before income tax expense and equity in earnings of an investee		48,903			42,255
	Income tax expense		(159	)		(203	)
	Equity in earnings of an investee		316			139


	Income from continuing operations		49,060			42,191
	Income from discontinued operations		900			3,806


	Net income	$	49,960		$	45,997




	Weighted average common shares outstanding		48,617			43,368




	Per common share:
	Income from continuing operations	$	1.01		$	0.97




	Income from discontinued operations	$	0.02		$	0.09




	Net income	$	1.03		$	1.06

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	12 Months Ended
Shareholders' Equity (Tables)	Dec. 31, 2013
Shareholders' Equity	'
Schedule of shares granted and vested	'






		Number			Weighted
		of			Average
		Shares			Grant Date
					Fair Value
	Unvested shares at December 31, 2010		70,520		$	27.96
	Granted in 2011		83,050			20.76
	Vested in 2011		(49,955	)		20.79


	Unvested shares at December 31, 2011		103,615			23.32
	Granted in 2012		83,617			15.99
	Vested in 2012		(71,244	)		15.75
	Forfeited in 2012		(1,285	)		18.74


	Unvested shares at December 31, 2012		114,703			19.39
	Granted in 2013		83,450			23.29
	Vested in 2013		(66,639	)		23.06
	Forfeited in 2013		(600	)		22.49


	Unvested shares at December 31, 2013		130,914			20.7

Cumulative_Other_Comprehensive1

Cumulative Other Comprehensive (Loss) Income (Tables)	12 Months Ended
Cumulative Other Comprehensive (Loss) Income (Tables)	Dec. 31, 2013
Cumulative Other Comprehensive (Loss) Income	'
Schedule of amounts recognized in cumulative other comprehensive (loss) income by component	'






		Year Ended December 31, 2013
		Unrealized			Foreign			Equity in			Total
		Gain (Loss)			Currency			Unrealized
		on Derivative			Translation			Gain (Loss) of
		Instruments			Adjustments			an Investee
	Balances as of December 31, 2012	$	(16,624	)	$	17,071		$	118		$	565


	Other comprehensive income (loss) before reclassifications		(103	)		(43,718	)		(79	)		(43,900	)
	Amounts reclassified from cumulative other comprehensive (loss) income to net loss		5,021			—			(17	)		5,004


	Net current period other comprehensive income (loss)		4,918			(43,718	)		(96	)		(38,896	)


	Balances as of December 31, 2013	$	(11,706	)	$	(26,647	)	$	22		$	(38,331	)




Schedule of reclassifications out of cumulative other comprehensive income (loss)	'






	Year Ended December 31, 2013
	Details about	Amounts Reclassified from			Affected Line Items
	Cumulative Other	Cumulative Other Comprehensive			in the
	Comprehensive Income (Loss) Components	Income (Loss) to Net Loss			Statement of Operations
	Interest rate swap contracts	$	5,021		Interest expense
	Unrealized gains and losses on available for sale securities		(17	)	Equity in earnings of investees


		$	5,004

Noncontrolling_Interest_in_Con1

Noncontrolling Interest in Consolidated Subsidiary (Tables)	12 Months Ended
Noncontrolling Interest in Consolidated Subsidiary (Tables)	Dec. 31, 2013
Noncontrolling Interest in Consolidated Subsidiary	'
Summary of changes in the entity's ownership interest in SIR and the effects on the equity attributable to the entity	'






		CommonWealth			Effect on the
		REIT			Equity
		Ownership			Attributable to
		Percentage of			CommonWealth
		SIR After			REIT Common
		Transaction			Shareholders
	Year Ended December 31, 2012:
	Increase in noncontrolling interest related to the SIR IPO in March 2012		70.5	%	($	23,857	)
	Increase in noncontrolling interest related to the issuance of SIR common shares pursuant to its equity compensation plan in September 2012		70.4	%		(253	)
	Increase in noncontrolling interest related to the issuance of SIR common shares in December 2012		56	%		(707	)


					($	24,817	)




	Year Ended December 31, 2013:
	Increase in noncontrolling interest related to the issuance of SIR common shares pursuant to its equity compensation plan in May 2013		55.99	%	$	32

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2013
Income Taxes	'
Schedule of components of provision for income taxes	'






		Year Ended December 31,
		2013			2012			2011
	Current:
	State	$	519		$	765		$	542
	Foreign		2,572			199			465


			3,091			964			1,007


	Deferred:
	State		—			—			—
	Foreign		(457	)		2,243			340


			(457	)		2,243			340


	Income tax provision	$	2,634		$	3,207		$	1,347




Schedule of reconciliation of effective tax rate and the U.S. Federal statutory income tax rate	'






		Year Ended December 31,
		2013			2012			2011
	Taxes at statutory U.S. federal income tax rate		35	%		35	%		35	%
	Dividends paid deduction		(35.00	)%		(35.00	)%		(35.00	)%
	State, local, and foreign income taxes, net of federal tax benefit		(1.71	)%		(4.20	)%		1.22	%


	Effective tax rate		(1.71	)%		(4.20	)%		1.22	%

Indebtedness_Tables

Indebtedness (Tables)	12 Months Ended
Indebtedness (Tables)	Dec. 31, 2013
Indebtedness	'
Schedule of outstanding indebtedness	'






		December 31,
		2013		2012
	Unsecured revolving credit facility, due October 2015, at LIBOR plus a premium	$	235,000	$	297,000
	Unsecured revolving credit facility, due March 2016, at LIBOR plus a premium⁽¹⁾		—		95,000
	Unsecured term loan, due December 2016, at LIBOR plus a premium		500,000		500,000
	Unsecured term loan, due July 2017, at LIBOR plus a premium⁽¹⁾		—		350,000
	Senior Notes, due 2014 at 5.75%		—		244,655
	Senior Notes, due 2015 at 6.40%		33,440		186,000
	Senior Notes, due 2015 at 5.75%		138,773		250,000
	Senior Notes, due 2016 at 6.25%		139,104		400,000
	Senior Notes, due 2017 at 6.25%		250,000		250,000
	Senior Notes, due 2018 at 6.65%		250,000		250,000
	Senior Notes, due 2019 at 7.50%		125,000		125,000
	Senior Notes, due 2020 at 5.875%		250,000		250,000
	Senior Notes, due 2042 at 5.75%		175,000		175,000
	Mortgage Notes Payable, due 2014 at 4.95%		12,040		12,356
	Mortgage Notes Payable, due 2015 at 5.99%		7,987		8,272
	Mortgage Notes Payable, due 2015 at 5.78%⁽²⁾		—		8,980
	Mortgage Notes Payable, due 2016 at 5.235%		116,000		116,000
	Mortgage Notes Payable, due 2016 at 5.689%⁽¹⁾		—		7,500
	Mortgage Notes Payable, due 2016 at 5.76%		—		7,474
	Mortgage Notes Payable, due 2016 at 6.03%		40,334		40,854
	Mortgage Notes Payable, due 2016 at 6.29%		144,522		146,264
	Mortgage Notes Payable, due 2016 at 7.36%		10,804		11,302
	Mortgage Notes Payable, due 2017 at 5.67%		41,275		41,275
	Mortgage Notes Payable, due 2017 at 5.68%		265,000		265,000
	Mortgage Notes Payable, due 2017 at 5.95%⁽¹⁾		—		18,447
	Mortgage Notes Payable, due 2019 at LIBOR plus a premium⁽³⁾		173,247		174,870
	Mortgage Notes Payable, due 2021 at 5.69%		28,391		28,793
	Mortgage Notes Payable, due 2021 at 5.30%		39,598		40,185
	Mortgage Notes Payable, due 2022 at 6.75%		3,456		3,759
	Mortgage Notes Payable, due 2023 at 6.14%⁽²⁾		—		12,650
	Mortgage Notes Payable, due 2026 at 5.71%		7,240		7,637


			2,986,211		4,324,273
	Unamortized net premiums and discounts		19,199		25,548


		$	3,005,410	$	4,349,821






	-1
	Represents indebtedness of SIR when SIR was a consolidated subsidiary of ours.

	-2
	These mortgage notes are included in liabilities related to properties held for sale at December 31, 2013. See Note 4 for additional information regarding our properties held for sale.

	-3
	Interest on this loan is payable at a spread over LIBOR but has been fixed for the first seven years to December 1, 2016 by a cash flow hedge which sets the rate at approximately 5.66%.

Summary of outstanding senior notes purchased for cash pursuant to a tender offer	'






	Senior Note	Principal		Purchase
	Senior Note	Principal		Price
	5.75% Senior Notes due February 15, 2014	$	145,612	$	148,746
	6.40% Senior Notes due February 15, 2015		152,560		164,140
	5.75% Senior Notes due November 1, 2015		111,227		121,047
	6.25% Senior Notes due August 15, 2016		260,896		292,218


		$	670,295	$	726,151




Schedule of required principal payments on outstanding debt	'

	The required principal payments due during the next five years and thereafter under all of our outstanding debt at December 31, 2013, excluding principal payments totaling $20,402 for mortgage debt related to properties classified as held for sale, are as follows:


	2014	$	18,826
	2015		421,821
	2016		948,708
	2017		560,592
	2018		254,614
	Thereafter		781,650


		$	2,986,211

Fair_Value_of_Assets_and_Liabi1

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
Fair Value of Assets and Liabilities (Tables)	Dec. 31, 2013
Fair Value of Assets and Liabilities	'
Schedule of assets and liabilities measured at fair value	'






					Fair Value at Reporting Date Using
	Description	Total			Quoted Prices in			Significant Other			Significant
					Active Markets for			Observable Inputs			Unobservable
					Identical Assets			(Level 2)			Inputs
					(Level 1)						(Level 3)
	Recurring Fair Value Measurements:
	Effective portion of interest rate contracts⁽¹⁾	$	(11,706	)	$	—		$	(11,706	)	$	—
	Non-Recurring Fair Value Measurements:
	Properties held for sale⁽²⁾	$	464,299		$	—		$	—		$	464,299


	-1
	The fair value of our interest rate swap contracts is determined using the net discounted cash flows of the expected cash flows of each derivative based on the market based interest rate curve (level 2 inputs) and adjusted for our credit spread and the actual and estimated credit spreads of the counterparties (level 3 inputs). Although we have determined that the majority of the inputs used to value our derivatives fall within level 2 of the fair value hierarchy, the credit valuation adjustments associated with our derivatives utilize level 3 inputs, such as estimates of current credit spreads, to evaluate the likelihood of default by us and the counterparties. As of December 31, 2013, we have assessed the significance of the impact of the credit valuation adjustments on the overall valuation of our derivative positions and have determined that the credit valuation adjustments are not significant to the overall valuation of our derivatives. As a result, we have determined that our derivative valuations in their entirety are classified as level 2 inputs in the fair value hierarchy.

	-2
	As of December 31, 2013, we recorded a net loss on asset impairment totaling $204,036 (excluding $23,086 of asset impairment recorded on properties sold during 2013) for three of our CBD properties (four buildings) and 36 of our suburban properties (89 buildings) to reduce the aggregate carrying value of these properties from $668,335 to their estimated fair value of $471,457, reflected in the table below, less costs to sell of $464,299. All of these properties were classified as held for sale as of December 31, 2013. We used third party broker information, independent appraisals and sales comparables (level 3 inputs), in determining the fair value of these properties. The valuation techniques and significant unobservable inputs used for our level 3 fair value measurements at December 31, 2013 were as follows:


	Description	Fair Value at			Primary		Unobservable		Range
		December 31,			Valuation		Inputs		(Weighted Average)
		2013			Techniques
	Properties held for sale on which we recognized impairment losses	$	471,457		Discounted cash flows		Discount rate		9% - 12% (10.3%)
							Exit capitalization rate		8% - 10% (8.8%)



Schedule of valuation techniques and significant unobservable inputs used for level 3 fair value measurements	'




	Description	Fair Value at			Primary		Unobservable		Range
		December 31,			Valuation		Inputs		(Weighted Average)
		2013			Techniques
	Properties held for sale on which we recognized impairment losses	$	471,457		Discounted cash flows		Discount rate		9% - 12% (10.3%)
							Exit capitalization rate		8% - 10% (8.8%)



Schedule of effects of interest rate derivatives on our consolidated statements of operations and consolidated statements of comprehensive (loss) income	'






		Year Ended December 31,
		2013			2012			2011
	Balance at beginning of year	($	16,624	)	($	15,796	)	($	6,956	)
	Amount of loss recognized in cumulative other comprehensive (loss) income		(103	)		(5,790	)		(13,804	)
	Amount of loss reclassified from cumulative other comprehensive (loss) income into interest expense		5,021			4,962			4,964


	Unrealized gain (loss) on derivative instruments		4,918			(828	)		(8,840	)


	Balance at end of year	($	11,706	)	($	16,624	)	($	15,796	)




Fair value and carrying value of financial instruments	'






		December 31, 2013						December 31, 2012
		Carrying			Fair			Carrying			Fair
		Amount			Value			Amount			Value
	Senior notes and mortgage notes payable	$	2,097,164		$	2,143,834		$	2,932,951		$	3,181,522

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
Segment Information (Tables)	Dec. 31, 2013
Segment Information	'
Schedule of property level information by geographic region and property type, property square feet	'






		As of December 31,
		2013			2012
	Square feet (in thousands):
	CBD properties		20,975			21,224
	Suburban properties		16,298			40,582


	Total properties		37,273			61,806









		Year Ended December 31,
		2013			2012			2011
	Rental income:
	CBD properties	$	432,812		$	408,144		$	320,564
	Suburban properties		274,568			301,246			281,068


	Total properties	$	707,380		$	709,390		$	601,632




	Tenant reimbursements and other income:
	CBD properties	$	118,314		$	112,083		$	79,277
	Suburban properties		59,842			60,432			60,435


	Total properties	$	178,156		$	172,515		$	139,712




	NOI:
	CBD properties	$	291,544		$	280,036		$	221,737
	Suburban properties		223,123			245,265			222,199


	Total properties	$	514,667		$	525,301		$	443,936




Schedule of reconciliation of NOI to net income	'






		Year Ended December 31,
		2013			2012			2011
	Rental income	$	707,380		$	709,390		$	601,632
	Tenant reimbursements and other income		178,156			172,515			139,712
	Operating expenses		(370,869	)		(356,604	)		(297,408	)


	NOI	$	514,667		$	525,301		$	443,936




	NOI	$	514,667		$	525,301		$	443,936
	Depreciation and amortization		(218,854	)		(209,759	)		(171,662	)
	General and administrative		(77,209	)		(46,057	)		(38,221	)
	Loss on asset impairment		—			—			(3,036	)
	Acquisition related costs		(318	)		(5,648	)		(9,731	)


	Operating income		218,286			263,837			221,286
	Interest and other income		1,229			1,404			1,662
	Interest expense		(173,011	)		(201,840	)		(191,876	)
	Loss on early extinguishment of debt		(60,052	)		(287	)		(35	)
	Gain on sale of equity investment		66,293			—			—
	Gain on issuance of shares by an equity investee		—			7,246			11,177


	Income from continuing operations before income tax expense and equity in earnings of investees		52,745			70,360			42,214
	Income tax expense		(2,634	)		(3,207	)		(1,347	)
	Equity in earnings of investees		25,754			11,420			11,377


	Income from continuing operations		75,865			78,573			52,244
	Income from discontinued operations		15,867			9,783			22,307
	Loss on asset impairment from discontinued operations		(227,122	)		(168,632	)		(7,319	)
	Loss on early extinguishment of debt from discontinued operations		(1,011	)		(1,608	)		—
	Net (loss) gain on sale of properties from discontinued operations		(22,162	)		2,039			42,752


	(Loss) income before gain on sale of properties		(158,563	)		(79,845	)		109,984
	Gain on sale of properties		1,596			—			—


	Net (loss) income	$	(156,967	)	$	(79,845	)	$	109,984

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
Selected Quarterly Financial Data (Unaudited) (Tables)	Dec. 31, 2013
Selected Quarterly Financial Data (Unaudited)	'
Selected Quarterly Financial Data (Unaudited)	'






		2013
		First			Second			Third			Fourth
		Quarter⁽¹⁾			Quarter⁽¹⁾			Quarter⁽¹⁾			Quarter
	Total revenues	$	242,653		$	246,181		$	198,283			$198,419
	Net income (loss) available for CommonWealth REIT common shareholders		14,516			7,738			(227,466	)		(16,452	)
	Net income (loss) available for CommonWealth REIT common shareholders per share—basic and diluted		0.15			0.07			(1.92	)		(0.14	)
	Common distributions declared		0.25			0.25			0.25			0.25





		2012
		First			Second			Third			Fourth
		Quarter⁽¹⁾			Quarter⁽¹⁾			Quarter⁽¹⁾			Quarter
	Total revenues	$	209,970		$	217,346		$	222,632		$	231,957
	Net income (loss) available for CommonWealth REIT common shareholders		9,857			2,242			(122	)		(163,935	)
	Net income (loss) available for CommonWealth REIT common shareholders per share—basic and diluted		0.12			0.03			—			(1.96	)
	Common distributions declared		0.5			0.5			0.5			0.25


	-1
	Amounts previously reported have been adjusted as follows:

Schedule of amounts previously reported and adjustments	'




		2013
		First			Second			Third
		Quarter			Quarter			Quarter
	Total revenues as previously reported	$	275,048		$	274,766		$	201,741
	Total revenues from properties reclassified to discontinued operations during 2013		(32,395	)		(28,585	)		(3,458	)


	Total revenues restated	$	242,653		$	246,181		$	198,283









		2012
		First			Second			Third			Fourth
		Quarter			Quarter			Quarter			Quarter
	Total revenues as previously reported	$	243,378		$	249,797		$	255,225		$	264,692
	Total revenues from properties reclassified to discontinued operations during 2013		(33,408	)		(32,451	)		(32,593	)		(32,735	)


	Total revenues restated	$	209,970		$	217,346		$	222,632		$	231,957

Organization_Details

Organization (Details)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Jul. 02, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Mar. 15, 2013

Dec. 31, 2012

Dec. 31, 2013

Mar. 12, 2012

Dec. 31, 2013

Dec. 31, 2012

Feb. 16, 2012

Dec. 31, 2013

sqft

Maximum

Consolidated portfolio

Wholly owned portfolio

SIR

GOV

Australia

SIR

sqft

CBD

Suburban property

Wholly owned portfolio

sqft

Previously reported

property

sqft

property

sqft

property

sqft

Organization

Properties owned

125

Number of buildings

195

144

Property square feet

37,273,000

61,806,000

37,273,000

20,975,000

16,298,000

1,759,000

21,400,000

Equity method investments, ownership percentage

50.00%

56.00%

44.20%

56.00%

0.00%

18.20%

44.20%

Ownership percentage prior to initial public offering

100.00%

Issuance of shares, net (in shares)

10,500,000

9,200,000

Wholly owned subsidiary, common shares owned

22,000,000

Ownership percentage

44.20%

56.00%

Equity investments, common shares owned

22,000,000

9,950,000

22,000,000

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2013
	trustee
Basis of Presentation	'
Percentage of investments in subsidiaries	100.00%
Number of common managing trustees	2
Maximum	'
Basis of Presentation	'
Maximum percentage of investment accounted for under equity method of accounting	50.00%
Buildings and improvements \| Maximum	'
Real Estate Properties	'
Maximum estimated useful life	'40 years
Personal property \| Maximum	'
Real Estate Properties	'
Maximum estimated useful life	'12 years

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	property	Dec. 31, 2012	Dec. 31, 2011
Real Estate Properties	'	'	'
Net reductions to rental income from amortization of capitalized above market and below market leases	$10,158	$10,274	$8,766
Net increases to income from discontinued operations from amortization of capitalized above market and below market leases	623	312	286
Amortization included in depreciation and amortization	47,586	45,475	32,907
Amortization included in income from discontinued operations	2,157	4,740	7,058
Future amortization of net intangible lease assets and liabilities	'	'	'
2014	46,204	'	'
2015	39,690	'	'
2016	32,172	'	'
2017	24,996	'	'
2018	20,876	'	'
Thereafter	57,939	'	'
Loss on asset impairment	204,036	'	'
Losses on asset impairment for properties sold	23,086	'	'
Number of properties impaired	39	'	'
Number of buildings impaired	93	'	'
Accrued environmental remediation costs	418	10,798	'
Other Assets, Net	'	'	'
Deferred financing fees	45,985	58,783	'
Accumulated amortization for deferred financing fees	21,455	21,623	'
Deferred financing fees for properties held for sale	272	'	'
Accumulated amortization for deferred financing fees for properties held for sale	132	'	'
Deferred leasing costs for properties held and used in operations	146,996	151,115	'
Accumulated amortization for deferred leasing costs for properties held and used in operations	46,228	49,652	'
Deferred leasing costs for properties held for sale	13,769	4,771	'
Accumulated amortization for deferred leasing costs for properties held for sale	987	2,110	'
Capitalized lease incentives for properties held and used in operations	20,651	20,491	'
Accumulated amortization for capitalized lease incentives for properties held and used in operations	5,392	3,828	'
Capitalized lease incentives for properties held for sale	590	'	'
Accumulated amortization for capitalized lease incentives for properties held for sale	40	'	'
Future amortization of deferred financing fees and leasing costs	'	'	'
Future amortization of deferred financing fees and leasing costs, in 2014	22,693	'	'
Future amortization of deferred financing fees and leasing costs, in 2015	21,041	'	'
Future amortization of deferred financing fees and leasing costs, in 2016	17,274	'	'
Future amortization of deferred financing fees and leasing costs, in 2017	14,233	'	'
Future amortization of deferred financing fees and leasing costs, in 2018	12,230	'	'
Future amortization of deferred financing fees and leasing costs, thereafter	37,827	'	'
Future amortization of capitalized lease incentives	'	'	'
Future amortization of capitalized lease incentives, in 2014	2,256	'	'
Future amortization of capitalized lease incentives, in 2015	2,236	'	'
Future amortization of capitalized lease incentives, in 2016	2,225	'	'
Future amortization of capitalized lease incentives, in 2017	2,152	'	'
Future amortization of capitalized lease incentives, in 2018	2,069	'	'
Future amortization of capitalized lease incentives, thereafter	4,321	'	'
Accounting Policy for Derivative Instruments	'	'	'
Fair value of derivative instrument	11,706	16,624	'
Income Taxes	'	'	'
Minimum percentage of likelihood of realization of tax benefits	50.00%	'	'
Foreign currency translation adjustments	-26,647	17,071	'
Above market leases	'	'	'
Real Estate Properties	'	'	'
Capitalized leases for properties held and used in operations	127,944	190,402	'
Accumulated amortization of capitalized leases for properties held and used in operations	48,841	56,374	'
Capitalized leases for properties held for sale	2,047	1,191	'
Accumulated amortization of capitalized leases for properties held for sale	0	1,060	'
Below market leases	'	'	'
Real Estate Properties	'	'	'
Capitalized leases for properties held and used in operations	56,815	106,643	'
Accumulated amortization of capitalized leases for properties held and used in operations	22,880	37,339	'
Capitalized leases for properties held for sale	4,996	92	'
Accumulated amortization of capitalized leases for properties held for sale	2,926	71	'
In place leases	'	'	'
Real Estate Properties	'	'	'
Capitalized leases for properties held and used in operations	282,754	393,068	'
Accumulated amortization of capitalized leases for properties held and used in operations	106,045	99,340	'
Capitalized leases for properties held for sale	9,351	2,297	'
Accumulated amortization of capitalized leases for properties held for sale	$4,461	$1,975	'

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details 3) (Series D)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Series D	'	'
Shareholders' Equity	'	'
Preferred shares, dividend yield (as a percent)	6.50%	6.50%
Percentage of average closing market price of the entity's common stock based on which ratio for conversion of preferred shares into common shares is determined	98.00%	'

Board_of_Trustees_Details

Board of Trustees (Details) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Feb. 26, 2013
	item
Board of Trustees	'
Number of independent trustees proposed to be removed under consent solicitation	2
Number of nominees for new trustee proposed by Related/Corvex in the event of the removal of independent trustees	7
Period from record date under consent solicitation	'30 days
Percentage of common stock to be held to submit nominations for successor trustees to be elected	1.00%
Market value of common stock to be held to submit nominations for successor trustees to be elected	$2,000
Period for submission of nominations for successor trustees to be elected as eligible shareholders	'1 year

Real_Estate_Properties_Details

Real Estate Properties (Details) (USD $)

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

In Thousands, unless otherwise specified

Jan. 31, 2013

Apr. 30, 2012

Dec. 31, 2013

Dec. 31, 2012

Feb. 28, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2013

Dec. 31, 2013

Nov. 30, 2013

Dec. 30, 2013

Oct. 30, 2013

Oct. 29, 2013

Jun. 29, 2013

Jun. 28, 2013

Dec. 31, 2013

Oct. 31, 2013

Aug. 31, 2013

Jun. 30, 2013

31-May-13

Apr. 30, 2013

Jan. 31, 2013

Mar. 31, 2013

property

sqft

property

Suburban property

CBD

Sale

sqft

property

item

CBD and suburban properties

Suburban property

CBD

property

sqft

Real estate properties information

Real estate improvements

$122,927

Aggregate sale price of properties sold, excluding closing costs

2,551

249,132

50,500

89,000

13,900

4,000

1,600

5,250

2,020

43,000

4,100

16,300

4,025

830

10,250

1,806

Property square feet

37,273,000

61,806,000

8,343,955

2,125,278

1,670,104

665,545

199,418

30,105

143,802

77,394

1,211,536

129,452

356,045

57,250

618,000

1,060,026

Number of land parcels sold

Mortgage financing related to suburban property sold

7,688

419

7,688

1,419

7,688

Interest rate on real estate mortgage receivable (as a percent)

6.00%

Net gains on sale of properties

$1,596

$1,765

($25,521)

$317

$1,277

$1,596

Number of Properties Sold

Number of Real Estate Properties Held for Sale

Number of buildings sold

134

Number of buildings held for sale

106

Property square feet, held for sale

8,425,548

6,673,851

Real_Estate_Properties_Details1

Real Estate Properties (Details 2) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Balance Sheets:	'	'
Real estate properties	$5,537,165	$7,829,409
Acquired real estate leases	255,812	427,756
Rents receivable, net	223,769	253,394
Other assets, net	188,675	211,293
Properties held for sale	573,531	171,832
Mortgage notes payable, net	914,510	984,827
Assumed real estate lease obligations	33,935	69,304
Rent collected in advance	27,553	35,700
Security deposits	11,976	23,860
Liabilities related to properties held for sale	28,734	2,339
Real estate properties held for sale	'	'
Balance Sheets:	'	'
Real estate properties	536,552	164,041
Acquired real estate leases	6,937	453
Rents receivable, net	14,180	2,791
Other assets, net	15,862	4,547
Properties held for sale	573,531	171,832
Mortgage notes payable, net	20,018	'
Assumed real estate lease obligations	2,070	21
Rent collected in advance	4,043	854
Security deposits	2,603	1,464
Liabilities related to properties held for sale	$28,734	$2,339

Real_Estate_Properties_Details2

Real Estate Properties (Details 3) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statements of Operations:	'	'	'	'	'	'	'	'	'	'	'
Rental income	'	'	'	'	'	'	'	'	$707,380	$709,390	$601,632
Tenant reimbursements and other income	'	'	'	'	'	'	'	'	178,156	172,515	139,712
Total revenues	198,419	198,283	246,181	242,653	231,957	222,632	217,346	209,970	885,536	881,905	741,344
Operating expenses	'	'	'	'	'	'	'	'	370,869	356,604	297,408
Depreciation and amortization	'	'	'	'	'	'	'	'	218,854	209,759	171,662
General and administrative	'	'	'	'	'	'	'	'	77,209	46,057	38,221
Acquisition related costs	'	'	'	'	'	'	'	'	318	5,648	9,731
Total expenses	'	'	'	'	'	'	'	'	667,250	618,068	520,058
Operating income	'	'	'	'	'	'	'	'	218,286	263,837	221,286
Interest and other income	'	'	'	'	'	'	'	'	1,229	1,404	1,662
Interest expense	'	'	'	'	'	'	'	'	-173,011	-201,840	-191,876
(Loss) income from discontinued operations	'	'	'	'	'	'	'	'	15,867	9,783	22,307
Discontinued operations, properties sold or held for sale	'	'	'	'	'	'	'	'	'	'	'
Statements of Operations:	'	'	'	'	'	'	'	'	'	'	'
Rental income	'	'	'	'	'	'	'	'	110,955	134,962	163,159
Tenant reimbursements and other income	'	'	'	'	'	'	'	'	18,453	22,128	27,905
Total revenues	'	'	'	'	'	'	'	'	129,408	157,090	191,064
Operating expenses	'	'	'	'	'	'	'	'	76,203	87,774	104,449
Depreciation and amortization	'	'	'	'	'	'	'	'	28,098	48,533	51,493
General and administrative	'	'	'	'	'	'	'	'	7,563	8,675	9,254
Acquisition related costs	'	'	'	'	'	'	'	'	'	'	471
Total expenses	'	'	'	'	'	'	'	'	111,864	144,982	165,667
Operating income	'	'	'	'	'	'	'	'	17,544	12,108	25,397
Interest and other income	'	'	'	'	'	'	'	'	65	79	58
Interest expense	'	'	'	'	'	'	'	'	-1,742	-2,404	-3,148
(Loss) income from discontinued operations	'	'	'	'	'	'	'	'	$15,867	$9,783	$22,307

Real_Estate_Properties_Details3

Real Estate Properties (Details 4) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	sqft	Dec. 31, 2012	Dec. 31, 2011
Real Estate Properties	'	'	'
Expenditures committed on leases executed during 2012	$128,486	'	'
Leases executed in 2013, square feet	5,152,000	'	'
Committed but unspent tenant related obligations based on executed leases as of December 31, 2013	89,986	'	'
Future minimum lease payments receivable:	'	'	'
2014	589,603	'	'
2015	564,468	'	'
2016	501,714	'	'
2017	441,682	'	'
2018	391,015	'	'
Thereafter	1,350,719	'	'
Total	3,839,201	'	'
Future minimum lease payments:	'	'	'
2014	1,477	'	'
2015	1,477	'	'
2016	1,477	'	'
2017	1,477	'	'
2018	1,483	'	'
Thereafter	131,496	'	'
Total	138,887	'	'
Ground lease expenses	$1,857	$1,828	$1,850

Investment_in_Direct_Financing2

Investment in Direct Financing Lease (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Investment in Direct Financing Lease	'	'
Percentage of term exceeding useful life of one office tower	75.00%	'
Total minimum lease payments receivable	$22,986	$31,084
Estimated unguaranteed residual value of leased asset	4,951	4,951
Unearned income	-8,174	-9,302
Net investment in direct financing lease	19,763	26,733
Allowance for losses related to our direct financing lease	0	0
Future minimum rentals receivable on direct financing lease	'	'
2014	8,098	'
2015	8,098	'
2016	226	'
2017	226	'
2018	226	'
Thereafter	6,112	'
Total	$22,986	'

Equity_Investments_Details

Equity Investments (Details) (USD $)

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

In Thousands, except Share data, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jul. 02, 2013

Dec. 31, 2013

Dec. 31, 2012

Mar. 15, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

SIR

GOV

AIC

Equity Investments

Equity method investments, ownership percentage

56.00%

44.20%

56.00%

18.20%

0.00%

18.20%

12.50%

25.00%

Equity Investments

$517,991

$184,711

$512,078

$173,452

$5,913

$11,259

Equity in Earnings

25,754

11,420

11,377

21,153

4,111

10,836

11,238

490

584

139

Equity investments, common shares owned

22,000,000

9,950,000

Equity investments, market value based on quoted market prices

588,280

Equity investments, quoted market price of common share (in dollars per share)

$26.74

Gross proceeds received on issuance or sale of common shares

250,740

Net proceeds received on issuance or sale of common shares

239,576

Common stock price per share (in dollars per share)

$28.25

$25.20

Ownership percentage after offering

44.20%

Market value of common shares exceeding carrying value

17,609

Amortization of the difference between carrying value and share of underlying equity

'34 years

Gain on issuance of shares by an equity investee

7,246

11,177

66,293

Cash distributions

$19,800

$4,279

$16,816

$16,617

Issuance of shares, net (in shares)

10,500,000

Equity_Investments_Details_2

Equity Investments (Details 2) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Balance Sheets:	'	'	'	'
Real estate properties, net	$4,642,106	$6,821,803	'	'
Acquired real estate leases, net	255,812	427,756	'	'
Cash and cash equivalents	222,449	102,219	192,763	194,040
Rents receivable, net	223,769	253,394	'	'
Other assets, net	188,675	211,293	'	'
Total assets	6,646,434	8,189,634	'	'
Revolving credit facility	235,000	297,000	'	'
Mortgage notes payable	914,510	984,827	'	'
Assumed real estate lease obligations, net	33,935	69,304	'	'
Other liabilities	165,855	194,184	'	'
Shareholders' equity	3,363,586	3,105,428	'	'
Total liabilities and shareholders' equity	6,646,434	8,189,634	'	'
SIR	'	'	'	'
Balance Sheets:	'	'	'	'
Real estate properties, net	1,579,234	1,249,081	'	'
Acquired real estate leases, net	129,426	95,248	'	'
Cash and cash equivalents	20,025	20,373	'	'
Rents receivable, net	55,335	38,885	'	'
Other assets, net	17,839	27,065	'	'
Total assets	1,801,859	1,430,652	'	'
Revolving credit facility	159,000	95,000	'	'
Term loan	350,000	350,000	'	'
Mortgage notes payable	27,147	27,778	'	'
Assumed real estate lease obligations, net	26,966	20,434	'	'
Other liabilities	40,055	37,257	'	'
Shareholders' equity	1,198,691	900,183	'	'
Total liabilities and shareholders' equity	1,801,859	1,430,652	'	'
GOV	'	'	'	'
Balance Sheets:	'	'	'	'
Real estate properties, net	'	1,311,202	'	'
Assets of discontinued operations	'	47,142	'	'
Acquired real estate leases, net	'	144,402	'	'
Cash and cash equivalents	'	5,255	'	'
Rents receivable, net	'	28,882	'	'
Other assets, net	'	25,251	'	'
Total assets	'	1,562,134	'	'
Revolving credit facility	'	49,500	'	'
Term loan	'	350,000	'	'
Mortgage notes payable	'	93,127	'	'
Liabilities of discontinued operations	'	298	'	'
Assumed real estate lease obligations, net	'	19,129	'	'
Other liabilities	'	22,629	'	'
Shareholders' equity	'	1,027,451	'	'
Total liabilities and shareholders' equity	'	$1,562,134	'	'

Equity_Investments_Details_3

Equity Investments (Details 3) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statements:	'	'	'	'	'	'	'	'	'	'	'
Rental income	'	'	'	'	'	'	'	'	$707,380	$709,390	$601,632
Tenant reimbursements and other income	'	'	'	'	'	'	'	'	178,156	172,515	139,712
Total revenues	198,419	198,283	246,181	242,653	231,957	222,632	217,346	209,970	885,536	881,905	741,344
Operating expenses	'	'	'	'	'	'	'	'	370,869	356,604	297,408
General and administrative	'	'	'	'	'	'	'	'	77,209	46,057	38,221
Total expenses	'	'	'	'	'	'	'	'	667,250	618,068	520,058
Operating income	'	'	'	'	'	'	'	'	218,286	263,837	221,286
Interest and other income	'	'	'	'	'	'	'	'	1,229	1,404	1,662
Interest expense	'	'	'	'	'	'	'	'	-173,011	-201,840	-191,876
Income from continuing operations before income tax expense and equity in earnings of investees	'	'	'	'	'	'	'	'	52,745	70,360	42,214
Income tax benefit (expense)	'	'	'	'	'	'	'	'	-2,634	-3,207	-1,347
Equity in earnings of investees	'	'	'	'	'	'	'	'	25,754	11,420	11,377
Income from continuing operations	'	'	'	'	'	'	'	'	75,865	78,573	52,244
Net (loss) income	'	'	'	'	'	'	'	'	-156,967	-79,845	109,984
SIR	'	'	'	'	'	'	'	'	'	'	'
Income Statements:	'	'	'	'	'	'	'	'	'	'	'
Rental income	'	'	'	'	'	'	'	'	159,011	105,559	91,775
Tenant reimbursements and other income	'	'	'	'	'	'	'	'	29,312	17,231	16,847
Total revenues	'	'	'	'	'	'	'	'	188,323	122,790	108,622
Operating expenses	'	'	'	'	'	'	'	'	36,382	23,796	22,946
Depreciation and amortization	'	'	'	'	'	'	'	'	31,091	14,860	11,205
Acquisition related costs	'	'	'	'	'	'	'	'	2,002	2,470	'
General and administrative	'	'	'	'	'	'	'	'	12,423	8,203	5,528
Total expenses	'	'	'	'	'	'	'	'	81,898	49,329	39,679
Operating income	'	'	'	'	'	'	'	'	106,425	73,461	68,943
Interest expense	'	'	'	'	'	'	'	'	-13,763	-7,565	'
Income from continuing operations before income tax expense and equity in earnings of investees	'	'	'	'	'	'	'	'	92,662	65,896	68,943
Income tax benefit (expense)	'	'	'	'	'	'	'	'	96	-290	'
Equity in earnings of investees	'	'	'	'	'	'	'	'	334	269	'
Net (loss) income	'	'	'	'	'	'	'	'	93,092	65,875	68,943
Weighted average common shares outstanding	'	'	'	'	'	'	'	'	44,565	27,122	'
Per common share:	'	'	'	'	'	'	'	'	'	'	'
Net income per common share (in dollars per share)	'	'	'	'	'	'	'	'	$2.09	$2.43	'
Equity method investments, ownership percentage	44.20%	'	'	'	'	'	'	'	44.20%	'	'
GOV	'	'	'	'	'	'	'	'	'	'	'
Income Statements:	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	'	'	'	'	'	'	'	'	203,700	168,074
Operating expenses	'	'	'	'	'	'	'	'	'	75,326	62,117
Depreciation and amortization	'	'	'	'	'	'	'	'	'	49,070	37,776
Acquisition related costs	'	'	'	'	'	'	'	'	'	1,614	3,504
General and administrative	'	'	'	'	'	'	'	'	'	11,924	10,469
Total expenses	'	'	'	'	'	'	'	'	'	137,934	113,866
Operating income	'	'	'	'	'	'	'	'	'	65,766	54,208
Interest and other income	'	'	'	'	'	'	'	'	'	29	104
Interest expense	'	'	'	'	'	'	'	'	'	-16,892	-12,057
Income from continuing operations before income tax expense and equity in earnings of investees	'	'	'	'	'	'	'	'	'	48,903	42,255
Income tax benefit (expense)	'	'	'	'	'	'	'	'	'	-159	-203
Equity in earnings of investees	'	'	'	'	'	'	'	'	'	316	139
Income from continuing operations	'	'	'	'	'	'	'	'	'	49,060	42,191
Income from discontinued operations	'	'	'	'	'	'	'	'	'	900	3,806
Net (loss) income	'	'	'	'	'	'	'	'	'	49,960	45,997
Weighted average common shares outstanding	'	'	'	'	'	'	'	'	'	48,617	43,368
Per common share:	'	'	'	'	'	'	'	'	'	'	'
Income from continuing operations (in dollars per share)	'	'	'	'	'	'	'	'	'	$1.01	$0.97
Income from discontinued operations (in dollars per share)	'	'	'	'	'	'	'	'	'	$0.02	$0.09
Net income per common share (in dollars per share)	'	'	'	'	'	'	'	'	'	$1.03	$1.06
AIC	'	'	'	'	'	'	'	'	'	'	'
Per common share:	'	'	'	'	'	'	'	'	'	'	'
Amount invested in equity investee	5,209	'	'	'	'	'	'	'	5,209	'	'
Combined carrying value of equity method investments	$5,913	'	'	'	'	'	'	'	$5,913	'	'
Number of other companies which are shareholders of related party	4	'	'	'	'	'	'	'	4	'	'
Equity method investments, ownership percentage	12.50%	'	'	'	'	'	'	'	12.50%	'	'

Real_Estate_Mortgages_Receivab1

Real Estate Mortgages Receivable (Details) (USD $)	1 Months Ended			12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Jan. 31, 2013	Apr. 30, 2012	Dec. 31, 2013	Dec. 31, 2012
	Sep. 30, 2013	property	Apr. 30, 2012	Dec. 31, 2013	Dec. 31, 2012
Real Estate Mortgages Receivable	'	'	'	'	'
Number of properties sold or agreed to be sold	'	3	'	'	'
Number of buildings sold	'	18	'	'	'
Mortgage financing related to sale of suburban property	'	$7,688	$419	$7,688	$1,419
Interest rate on real estate mortgage receivable (as a percent)	'	6.00%	6.00%	'	'
Amount received from prepayment of real estate mortgage receivable	1,000	'	'	'	'
Total real estate mortgage receivable included in other assets, carrying value	'	'	'	$8,107	$1,419

Shareholders_Equity_Details

Shareholders' Equity (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
RMR	'	'	'
Award Plan	'	'	'
Number of shares granted under the Award Plan	73,450	71,617	73,050
Award vesting period	'4 years	'	'
Award Plan \| Officers and employees \| RMR	'	'	'
Award Plan	'	'	'
Award vesting period	'5 years	'	'
Award Plan \| Trustees	'	'	'
Award Plan	'	'	'
Number of shares granted under the Award Plan	2,000	2,000	2,000
Aggregate market value of shares granted under the Award Plan	201	226	266
Market value of common shares awarded to each trustee (in dollars)	40	37	53

Shareholders_Equity_Details_2

Shareholders' Equity (Details 2) (USD $)

3 Months Ended

12 Months Ended

1 Months Ended

In Thousands, except Share data, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Jan. 31, 2014

SIR

2014

2015

2016

2017

Award Plan

Distribution declared

Distributions

Distributions on common stock declared (in dollars per share)

$0.25

$0.50

$1.75

$0.25

Distributions paid or declared on common shares

$29,597

Ordinary income (as a percent)

0.00%

61.72%

65.90%

Number of Shares

Unvested shares at the beginning of the period

114,703

103,615

70,520

Granted in the period (in shares)

2,000

83,450

83,617

83,050

Vested in the period (in shares)

-47,868

-40,593

-27,843

-14,610

-66,639

-71,244

-49,955

Forfeited in the period (in shares)

-600

-1,285

Unvested shares at the end of the period

130,914

114,703

103,615

Weighted Average Grant Date Fair Value

Unvested shares at the beginning of the period (in dollars per share)

$19.39

$23.32

$27.96

Granted in the period (in dollars per share)

$23.29

$15.99

$20.76

Vested in the period (in dollars per share)

$23.06

$15.75

$20.79

Forfeited in the period (in dollars per share)

$22.49

$18.74

Unvested shares at the end of the period (in dollars per share)

$20.70

$19.39

$23.32

Estimated future compensation expense for the unvested shares

3,052

Common stock shares closing price per share

$23.31

Weighted average period over which the compensation expense will be recorded

'22 months

Compensation expense

$355

$507

$1,758

$1,179

$1,139

Shares available for issuance under the Award Plan

2,833,533

Return of capital (as a percent)

100.00%

38.28%

23.54%

Internal revenue code section 1250 gain (as a percent)

0.00%

7.34%

Capital gain (as a percent)

0.00%

3.22%

Shareholders_Equity_Details_3

Shareholders' Equity (Details 3) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Feb. 07, 2014	Jan. 28, 2014
			RMR	Common Shares
				Trustees
				Subsequent Event
				trustee
Shareholders' Equity	'	'	'	'
Common shares issued	'	'	12,187	'
Shares of beneficial interest granted	'	'	'	2,000
Par value of shares of beneficial interest (in dollars per share)	$0.01	$0.01	'	$0.01
Price per common share (in dollars per share)	'	'	'	$23.46
Number of recently appointed trustees to whom common shares granted	'	'	'	2

Shareholders_Equity_Details_4

Shareholders' Equity (Details 4) (USD $)	12 Months Ended
Shareholders' Equity (Details 4) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Series D	'	'
Shareholders' Equity	'	'
Preferred shares outstanding	15,180,000	15,180,000
Preferred shares dividend (in dollars per share)	$1.63	'
Preferred shares, dividend yield (as a percent)	6.50%	6.50%
Liquidation preference (in dollars per share)	$25	'
Initial conversion rate	0.480775	'
Initial conversion price per share (in dollars per share)	$52	'
Additional common shares	7,298,165	'
Percentage of average closing market price of the entity's common stock based on which ratio for conversion of preferred shares into common shares is determined	98.00%	'
Purchase price as a percentage of liquidation preference	100.00%	'
Series E	'	'
Shareholders' Equity	'	'
Preferred shares outstanding	11,000,000	11,000,000
Preferred shares dividend (in dollars per share)	$1.81	'
Preferred shares, dividend yield (as a percent)	7.25%	7.25%
Liquidation preference (in dollars per share)	$25	'
Redemption price per share (in dollars per share)	$25	'

Cumulative_Other_Comprehensive2

Cumulative Other Comprehensive (Loss) Income (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Roll forward of amounts recognized in cumulative other comprehensive (loss) income by component	'
Balances at beginning of period	$565
Other comprehensive income (loss) before reclassifications	-43,900
Amounts reclassified from cumulative other comprehensive (loss) income to net loss	5,004
Net current period other comprehensive income (loss)	-38,896
Balances at end of period	-38,331
Unrealized Gain (Loss) on Derivative Instruments	'
Roll forward of amounts recognized in cumulative other comprehensive (loss) income by component	'
Balances at beginning of period	-16,624
Other comprehensive income (loss) before reclassifications	-103
Amounts reclassified from cumulative other comprehensive (loss) income to net loss	5,021
Net current period other comprehensive income (loss)	4,918
Balances at end of period	-11,706
Foreign Currency Translation Adjustments	'
Roll forward of amounts recognized in cumulative other comprehensive (loss) income by component	'
Balances at beginning of period	17,071
Other comprehensive income (loss) before reclassifications	-43,718
Net current period other comprehensive income (loss)	-43,718
Balances at end of period	-26,647
Equity in Unrealized Gain (Loss) of an Investee	'
Roll forward of amounts recognized in cumulative other comprehensive (loss) income by component	'
Balances at beginning of period	118
Other comprehensive income (loss) before reclassifications	-79
Amounts reclassified from cumulative other comprehensive (loss) income to net loss	-17
Net current period other comprehensive income (loss)	-96
Balances at end of period	$22

Cumulative_Other_Comprehensive3

Cumulative Other Comprehensive (Loss) Income (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reclassifications out of cumulative other comprehensive income (loss)	'	'	'
Interest expenses	$173,011	$201,840	$191,876
Equity in earnings of investees	-25,754	-11,420	-11,377
Total reclassifications	-5,004	'	'
Cumulative Other Comprehensive Income (Loss) to Net Loss	'	'	'
Reclassifications out of cumulative other comprehensive income (loss)	'	'	'
Total reclassifications	5,004	'	'
Unrealized gains and losses on available for sale securities	'	'	'
Reclassifications out of cumulative other comprehensive income (loss)	'	'	'
Total reclassifications	17	'	'
Unrealized gains and losses on available for sale securities \| Cumulative Other Comprehensive Income (Loss) to Net Loss	'	'	'
Reclassifications out of cumulative other comprehensive income (loss)	'	'	'
Equity in earnings of investees	-17	'	'
Interest rate swap contracts \| Cumulative Other Comprehensive Income (Loss) to Net Loss	'	'	'
Reclassifications out of cumulative other comprehensive income (loss)	'	'	'
Interest expenses	$5,021	'	'

Noncontrolling_Interest_in_Con2

Noncontrolling Interest in Consolidated Subsidiary (Details) (SIR, USD $)	0 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 12, 2012	Dec. 31, 2013	Dec. 31, 2012
Noncontrolling Interest in Consolidated Subsidiary	'	'	'
Less than wholly owned subsidiary, common shares owned	'	22,000,000	22,000,000
Equity method investments, ownership percentage	'	44.20%	'
Less than wholly owned subsidiary, parent ownership interest percentage	'	'	56.00%
Ownership percentage prior to initial public offering	100.00%	100.00%	'
Effect on the Equity Attributable to CommonWealth REIT Common Shareholders	'	'	($24,817)
IPO	'	'	'
Noncontrolling Interest in Consolidated Subsidiary	'	'	'
CommonWealth REIT Ownership Percentage of SIR After Transaction (as a percent)	'	'	70.50%
Effect on the Equity Attributable to CommonWealth REIT Common Shareholders	'	'	-23,857
Equity compensation plan	'	'	'
Noncontrolling Interest in Consolidated Subsidiary	'	'	'
CommonWealth REIT Ownership Percentage of SIR After Transaction (as a percent)	'	55.99%	70.40%
Effect on the Equity Attributable to CommonWealth REIT Common Shareholders	'	32	-253
Common Shares	'	'	'
Noncontrolling Interest in Consolidated Subsidiary	'	'	'
CommonWealth REIT Ownership Percentage of SIR After Transaction (as a percent)	'	'	56.00%
Effect on the Equity Attributable to CommonWealth REIT Common Shareholders	'	'	($707)

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current:	'	'	'
State	$519	$765	$542
Foreign	2,572	199	465
Current tax	3,091	964	1,007
Deferred:	'	'	'
Foreign	-457	2,243	340
Deferred tax	-457	2,243	340
Income tax provision	2,634	3,207	1,347
Reconciliation of effective tax rate and the U.S. Federal statutory income tax rate	'	'	'
Taxes at statutory U.S. federal income tax rate (as a percent)	35.00%	35.00%	35.00%
Dividends paid deduction (as a percent)	-35.00%	-35.00%	-35.00%
State, local, and foreign income taxes, net of federal tax benefit (as a percent)	-1.71%	-4.20%	1.22%
Effective tax rate (as a percent)	-1.71%	-4.20%	1.22%
Deferred tax assets	2,601	2,329	'
Deferred tax liabilities	3,287	3,643	'
Valuation allowance	$511	$598	'

Related_Person_Transactions_De

Related Person Transactions (Details) (USD $)

1 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Jan. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Mar. 12, 2012

Feb. 16, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Jul. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 19, 2013

Dec. 31, 2013

Dec. 19, 2013

Dec. 31, 2013

Mar. 15, 2013

Dec. 31, 2013

Dec. 31, 2009

Sep. 30, 2011

Jan. 31, 2011

Dec. 31, 2013

Mar. 31, 2011

Dec. 31, 2008

Jun. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

property

sqft

SIR

Maximum

RMR

RMR Australia

GOV

SNH

AIC

sqft

item

property

item

office

SIR

Restricted shares

Maximum

Amended Agreement

property

sqft

Agreement to sell

item

sqft

item

Maximum

sqft

property

sqft

Related person transactions

Number of employees

Number of agreements

Number of entities independent trustees serving as independent directors or independent trustees of other public companies to which related party provides management services

Base management fee payable as a percentage of average historical cost of real estate investments, up to specified amount

0.70%

Threshold amount of real estate investments for payment of base management fee

$250,000,000

Base management fee payable as a percentage of average historical cost of real estate investments, located outside the United States, Puerto Rico and Canada

1.00%

Base management fee payable as a percentage of average historical cost of real estate investments, exceeding specified amount

0.50%

Base management fee payable as a percentage of average closing price per share of common shares on NYSE

0.70%

Base management fee payable, average market capitalization

250,000,000

Base management fee payable as a percentage of average market capitalization exceeding specified amount

0.50%

Threshold amount of average market capitalization for payment of base management fee

250,000,000

Base business management fee payable in cash (as a percent)

90.00%

Base business management fee payable in common shares (as a percent)

10.00%

Incentive management fee payable (as a percent)

12.00%

Measurement period of incentive management fee

'3 years

Portion of shares issued in payment of an incentive management fee

33.00%

Portion of remaining shares to be vested in equal annual installments

67.00%

Number of equal annual installments for vesting of common shares

Number of times registration right can be exercisable

Base management fee payable as a percentage of average historical cost of real estate investments, located in the United States, Puerto Rico and Canada

0.70%

Annual business management fee as a percentage of aggregate cost of properties acquired in excess of $250,000

0.50%

Incentive fee as a percentage of the product of weighted average common shares outstanding on a fully diluted basis and the excess, if any of the Normalized FFO Per Share for current fiscal year over the preceding fiscal year

15.00%

Business management fees

39,203,000

43,279,000

43,646,000

Incentive fees paid

Property management fees as a percentage of gross collected rents

3.00%

Construction supervision fees as a percentage of construction costs

5.00%

Property management and construction supervision fees

30,315,000

32,460,000

33,689,000

Compensation for business management and real estate investment services as a percentage of average historical cost of CWHAT's real estate investments

0.50%

Compensation for property management services as a percentage of difference between 3.0% of collected gross rents and the aggregate of all amounts paid or payable by or on behalf of CWHAT to third party property managers

50.00%

Compensation for construction supervision services as a percentage of difference between 5.0% of constructions costs and any amounts paid to third parties for construction management and/or supervision

50.00%

Business and property management fees

1,626,000

Payments to MacarthurCook Fund Management Limited

161,000

1,814,000

1,856,000

Pro rata share of related party's costs of providing internal audit function

296,000

355,000

240,000

Successive renewal period for business and property management agreements

'1 year

Period of prior written notice for termination of either agreement by entity or related party

'60 days

Number of business days notice for termination of either agreement by related party, if entity undergoes a change of control

'5 days

Number of regional offices leased

Rental income earned

828,000

564,000

566,000

Lease term

'3 years

Square feet

37,273,000

61,806,000

21,400,000

32,500

1,310,000

2,803,000

Number of shares granted under the Award Plan

2,000

73,450

71,617

73,050

73,450

71,617

73,050

Aggregate value of restricted shares granted (in dollars)

1,742,000

1,111,000

1,458,000

Vesting rights percentage for restricted shares vesting on the grant date

20.00%

Vesting rights percentage for restricted shares vesting on each of the next four anniversaries of the grant date

20.00%

Number of anniversaries of the grant date for vesting of restricted shares

'4 years

Ownership percentage prior to transaction

100.00%

Minimum ownership of outstanding common shares of related party required to engage the same manager or common managing trustees

10.00%

Shares sold

9,200,000

9,950,000

Net proceeds received on sale of common shares

239,576,000

Realized gain on sale of common shares

66,293,000

Amount of reimbursements payable to related party

9,385,000

12,958,000

636,000

310,000

Shares owned by related party

250,000

Less than wholly owned subsidiary, common shares owned

22,000,000

Less than wholly owned subsidiary, parent ownership interest percentage

56.00%

Proceeds from Issuance Initial Public Offering

180,814,000

Repayment of promissory note

400,000,000

Common shares consideration received on transfer of properties

22,000,000

Number of properties sold or transferred or agreed to be sold or transferred

Number of separate buildings or land parcels sold or transferred or agreed to be sold or transferred

251

Number of Properties Sold

Number of maximum MOBs, in respect of which right of first refusal to purchase is granted

Number of buildings sold

Aggregate sale price of properties sold, excluding closing costs

167,000,000

470,000,000

Net gains on sale of properties

1,596,000

7,846,000

168,272,000

Number of other companies which are shareholders of related party

Equity method investments, ownership percentage

44.20%

50.00%

12.50%

Amount invested in equity investee

5,209,000

Period for which property insurance program was purchased

'1 year

Coverage amount for property insurance

500,000,000

Premium for property insurance

5,984,000

6,560,000

6,697,000

Aggregate non-indemnifiable coverage of combined directors' and officers' liability insurance policy purchased by the entity

10,000,000

Aggregate excess coverage of combined directors' and officers' liability insurance policy purchased

5,000,000

Premium paid for combined directors' and officers' liability insurance policy

133,000

Legal fees and costs

$30,392,000

Indebtedness_Details

Indebtedness (Details) (USD $)

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Mar. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Oct. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Jun. 19, 2013

Real estate properties held for sale

Unsecured revolving credit facility, due October 2015

Unsecured revolving credit facility, due March 2016

Unsecured term loan, due December 2016

Unsecured term loan, due July 2017

Senior Notes, due 2014 at 5.75%

Senior Notes, due 2015 at 6.40%

Senior Notes, due 2015 at 5.75%

Senior Notes, due 2016 at 6.25%

Senior Notes, due 2017 at 6.25%

Senior Notes, due 2018 at 6.65%

Senior Notes, due 2019 at 7.50%

Senior Notes, due 2020 at 5.875%

Senior Notes, due 2042 at 5.75%

Mortgage notes maturing from 2014 through 2026

Mortgage Notes Payable, due 2014 at 4.95%

Mortgage Notes Payable, due 2015 at 5.99%

Mortgage Notes Payable, due 2015 at 5.78%

Mortgage Notes Payable, due 2016 at 5.235%

Mortgage Notes Payable, due 2016 at 5.689%

Mortgage Notes Payable, due 2016 at 5.76%

Mortgage Notes Payable, due 2016 at 6.03%

Mortgage Notes Payable, due 2016 at 6.29%

Mortgage Notes Payable, due 2016 at 7.36%

Mortgage Notes Payable, due 2017 at 5.67%

Mortgage Notes Payable, due 2017 at 5.68%

Mortgage Notes Payable, due 2017 at 5.95%

Mortgage Notes Payable, due 2019

Mortgage Notes Payable, due 2021 at 5.69%

Mortgage Notes Payable, due 2021 at 5.30%

Mortgage Notes Payable, due 2022 at 6.75%

Mortgage Notes Payable, due 2023 at 6.14%

Mortgage Notes Payable, due 2026 at 5.71%

Unsecured revolving credit facility and unsecured term loan

property

Indebtedness

Outstanding indebtedness

$2,986,211

$4,324,273

$20,402

$235,000

$297,000

$95,000

$500,000

$350,000

$244,655

$33,440

$186,000

$138,773

$250,000

$139,104

$400,000

$250,000

$125,000

$250,000

$175,000

$12,040

$12,356

$7,987

$8,272

$8,980

$116,000

$7,500

$7,474

$40,334

$40,854

$144,522

$146,264

$10,804

$11,302

$41,275

$265,000

$18,447

$173,247

$174,870

$28,391

$28,793

$39,598

$40,185

$3,456

$3,759

$12,650

$7,240

$7,637

Less unamortized net premiums and discounts

19,199

25,548

Total

3,005,410

4,349,821

Interest rate stated percentage

5.75%

6.40%

5.75%

6.25%

6.65%

7.50%

5.88%

5.75%

4.95%

5.99%

5.78%

5.24%

5.69%

5.76%

6.03%

6.29%

7.36%

5.67%

5.68%

5.95%

5.69%

5.30%

6.75%

6.14%

5.71%

Period for which interest on loan payable is fixed by a cash flow hedge

'7 years

Average interest rate mortgages (as a percent)

5.66%

Principal

670,295

145,612

152,560

111,227

260,896

Purchase Price

726,151

148,746

164,140

121,047

292,218

Loss on early extinguishment of debt

-60,027

-60,052

-287

-35

-1,011

Prepayment of debt

99,043

7,093

Maximum borrowing capacity

750,000

Maximum amount of borrowing

1,500,000

Maturity date extension period available

'1 year

Increased maximum borrowing capacity available under specified circumstances

1,000,000

Variable rate basis

'LIBOR

Basis points on variable rate (as a percent)

1.50%

1.85%

Facility fee of lending commitments under our revolving credit facility (as a percent)

0.35%

Interest rate payable (as a percent)

1.70%

2.00%

2.10%

Average interest rate (as a percent)

1.70%

1.50%

2.00%

1.80%

Amount outstanding

235,000

Available Borrowing Capacity

515,000

Percentage holding of aggregate credit exposure required by lender to accelerate payment in case of default

67.00%

Percentage holding of aggregate credit exposure required by lender to accelerate payment

51.00%

Number of Real Estate Properties Secured by Mortgage

Number of buildings secured by mortgage

Cost of properties mortgaged

5,537,165

7,829,409

536,552

164,041

1,269,185

Mortgaged properties aggregate net book value

4,642,106

6,821,803

1,109,259

Mortgage notes payable, net

914,510

984,827

20,018

914,510

Percentage of principal amount at which the potential acquiring entity may offer to repurchase the note

51.00%

Principal payments due

2014

18,826

2015

421,821

2016

948,708

2017

560,592

2018

254,614

Thereafter

781,650

Total

$2,986,211

$4,324,273

$20,402

$235,000

$297,000

$95,000

$500,000

$350,000

$244,655

$33,440

$186,000

$138,773

$250,000

$139,104

$400,000

$250,000

$125,000

$250,000

$175,000

$12,040

$12,356

$7,987

$8,272

$8,980

$116,000

$7,500

$7,474

$40,334

$40,854

$144,522

$146,264

$10,804

$11,302

$41,275

$265,000

$18,447

$173,247

$174,870

$28,391

$28,793

$39,598

$40,185

$3,456

$3,759

$12,650

$7,240

$7,637

Fair_Value_of_Assets_and_Liabi2

Fair Value of Assets and Liabilities (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Nonrecurring Fair Value Measurements:	'	'	'
Properties held for sale	$4,642,106	$6,821,803	'
Losses on asset impairment for properties sold	23,086	'	'
Effects of interest rate derivatives on our consolidated statements of operations and consolidated statements of comprehensive income (loss)	'	'	'
Unrealized gain (loss) on derivative instruments	4,918	-828	-8,840
CBD Office	'	'	'
Nonrecurring Fair Value Measurements:	'	'	'
Net Loss on asset impairment	204,036	'	'
Losses on asset impairment for properties sold	23,086	'	'
Interest Rate Swap	'	'	'
Recurring Fair Value Measurements:	'	'	'
Interest rate swap agreements qualifying as cash flow hedges used for hedging mortgage note payable	173,247	'	'
Derivative, variable rate basis	'LIBOR	'	'
Interest Rate Swap \| Cash Flow Hedges	'	'	'
Recurring Fair Value Measurements:	'	'	'
Effective portion of interest rate swap contracts	-11,706	-16,624	-15,796
Nonrecurring Fair Value Measurements:	'	'	'
Decrease (Increase) in fair value of interest rate cash flow hedges	4,918	828	'
Effects of interest rate derivatives on our consolidated statements of operations and consolidated statements of comprehensive income (loss)	'	'	'
Balance at beginning of year	-16,624	-15,796	-6,956
Amount of income (loss) recognized in cumulative other comprehensive (loss) income	-103	-5,790	-13,804
Amount of loss reclassified from cumulative other comprehensive (loss) income into interest expense	5,021	4,962	4,964
Unrealized gain (loss) on derivative instruments	4,918	-828	-8,840
Balance at end of year	-11,706	-16,624	-15,796
Reclassification from cumulative other comprehensive income (loss) into interest expense, over the next 12 months	4,862	'	'
Recurring \| Total Fair value	'	'	'
Recurring Fair Value Measurements:	'	'	'
Effective portion of interest rate swap contracts	-11,706	'	'
Effects of interest rate derivatives on our consolidated statements of operations and consolidated statements of comprehensive income (loss)	'	'	'
Balance at end of year	-11,706	'	'
Recurring \| Fair Value at Reporting Date Using Significant Other Observable Inputs (Level 2)	'	'	'
Recurring Fair Value Measurements:	'	'	'
Effective portion of interest rate swap contracts	-11,706	'	'
Effects of interest rate derivatives on our consolidated statements of operations and consolidated statements of comprehensive income (loss)	'	'	'
Balance at end of year	-11,706	'	'
Nonrecurring \| Carrying Amount \| Suburban Office Industrial and Other	'	'	'
Nonrecurring Fair Value Measurements:	'	'	'
Properties held for sale	668,335	'	'
Nonrecurring \| Total Fair value	'	'	'
Nonrecurring Fair Value Measurements:	'	'	'
Properties held for sale	464,299	'	'
Nonrecurring \| Total Fair value \| Suburban Office Industrial and Other	'	'	'
Nonrecurring Fair Value Measurements:	'	'	'
Properties held for sale	464,299	'	'
Nonrecurring \| Fair Value at Reporting Date Using Significant Unobservable Inputs (Level 3)	'	'	'
Nonrecurring Fair Value Measurements:	'	'	'
Properties held for sale	$464,299	'	'
Nonrecurring \| Fair Value at Reporting Date Using Significant Unobservable Inputs (Level 3) \| Suburban Office	'	'	'
Nonrecurring Fair Value Measurements:	'	'	'
Number of Available for Sale Real Estate Properties Held for Sale Expected to Sell within One Year	36	'	'
Number of Available for Sale Real Estate buildings Held for Sale Expected to Sell within One Year	89	'	'
Nonrecurring \| Fair Value at Reporting Date Using Significant Unobservable Inputs (Level 3) \| CBD Office	'	'	'
Nonrecurring Fair Value Measurements:	'	'	'
Number of Available for Sale Real Estate Properties Held for Sale Expected to Sell within One Year	3	'	'
Number of Available for Sale Real Estate buildings Held for Sale Expected to Sell within One Year	4	'	'

Fair_Value_of_Assets_and_Liabi3

Fair Value of Assets and Liabilities (Details 2) (Properties held for sale for which we recognized impairment losses, Discounted cash flows, Level 3, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Fair Value of Assets and Liabilities	'
Fair value of assets	471,457
Minimum	'
Valuation techniques and significant unobservable inputs	'
Discount rate (as a percent)	9.00%
Exit capitalization rate (as a percent)	8.00%
Maximum	'
Valuation techniques and significant unobservable inputs	'
Discount rate (as a percent)	12.00%
Exit capitalization rate (as a percent)	10.00%
(Weighted Average)	'
Valuation techniques and significant unobservable inputs	'
Discount rate (as a percent)	10.30%
Exit capitalization rate (as a percent)	8.80%

Fair_Value_of_Assets_and_Liabi4

Fair Value of Assets and Liabilities (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
	Total rents	Carrying Amount	Carrying Amount	Fair Value	Fair Value
	Credit concentration
Fair value of financial instruments	'	'	'	'	'
Senior notes and mortgage notes payable	'	$2,097,164	$2,932,951	$2,143,834	$3,181,522
Concentration risk, percentage	3.00%	'	'	'	'

Segment_Information_Details

Segment Information (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012
	property	sqft		sqft
	sqft
Segment information	'	'	'	'
Number of reportable segments	2	'	'	'
Number of geographical regions comprised mainly by properties owned by SIR	1	'	'	'
Number of remaining geographical regions	2	'	'	'
Square feet	37,273,000	61,806,000	'	'
Rental income	$707,380	$709,390	$601,632	'
Tenant reimbursements and other income	178,156	172,515	139,712	'
NOI	514,667	525,301	443,936	'
Investment in properties, net of accumulated depreciation	4,642,106	6,821,803	'	'
Minimum	'	'	'	'
Segment information	'	'	'	'
Percentage of CBD and suburban properties that are office properties	90.00%	'	'	'
CBD Properties	'	'	'	'
Segment information	'	'	'	'
Number of Real Estate Properties	38	'	'	'
Number of buildings	51	'	'	'
Square feet	20,975,000	21,224,000	'	20,166,000
Rental income	432,812	408,144	320,564	'
Tenant reimbursements and other income	118,314	112,083	79,277	'
NOI	291,544	280,036	221,737	'
Investment in properties, net of accumulated depreciation	3,001,397	3,176,446	'	'
CBD Properties \| Australia	'	'	'	'
Segment information	'	'	'	'
Investment in properties, net of accumulated depreciation	141,966	168,220	'	'
Suburban Properties	'	'	'	'
Segment information	'	'	'	'
Number of Real Estate Properties	87	'	'	'
Number of buildings	144	'	'	'
Square feet	16,298,000	40,582,000	'	41,567,000
Rental income	274,568	301,246	281,068	'
Tenant reimbursements and other income	59,842	60,432	60,435	'
NOI	223,123	245,265	222,199	'
Investment in properties, net of accumulated depreciation	1,640,709	3,645,357	'	'
Suburban Properties \| Australia	'	'	'	'
Segment information	'	'	'	'
Investment in properties, net of accumulated depreciation	$88,935	$104,010	'	'

Segment_Information_Details_2

Segment Information (Details 2) (USD $)	1 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Information	'	'	'	'
Rental income	'	$707,380	$709,390	$601,632
Tenant reimbursements and other income	'	178,156	172,515	139,712
Operating expenses	'	-370,869	-356,604	-297,408
NOI	'	514,667	525,301	443,936
Reconciliation of NOI to net income	'	'	'	'
NOI	'	514,667	525,301	443,936
Depreciation and amortization	'	-218,854	-209,759	-171,662
General and administrative	'	-77,209	-46,057	-38,221
Loss on asset impairment	'	'	'	-3,036
Acquisition related costs	'	-318	-5,648	-9,731
Operating income	'	218,286	263,837	221,286
Interest and other income	'	1,229	1,404	1,662
Interest expense	'	-173,011	-201,840	-191,876
Loss on early extinguishment of debt	-60,027	-60,052	-287	-35
Gain on sale of equity investment	'	66,293	'	'
Gain on issuance of shares by an equity investee	'	'	7,246	11,177
Income from continuing operations before income tax expense and equity in earnings of investees	'	52,745	70,360	42,214
Income tax expense	'	-2,634	-3,207	-1,347
Equity in earnings of investees	'	25,754	11,420	11,377
Income from continuing operations	'	75,865	78,573	52,244
Income from discontinued operations	'	15,867	9,783	22,307
Loss on asset impairment from discontinued operations	'	-227,122	-168,632	-7,319
Loss on early extinguishment of debt from discontinued operations	'	-1,011	-1,608	'
Net gain on sale of properties from discontinued operations	'	-22,162	2,039	42,752
(Loss) income before gain on sale of properties	'	-158,563	-79,845	109,984
Gain on sale of properties	'	1,596	'	'
Net (loss) income	'	($156,967)	($79,845)	$109,984

Selected_Quarterly_Financial_D2

Selected Quarterly Financial Data (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of unaudited quarterly results of operations	'	'	'	'	'	'	'	'	'	'	'
Total revenues	$198,419	$198,283	$246,181	$242,653	$231,957	$222,632	$217,346	$209,970	$885,536	$881,905	$741,344
Net income (loss) available for CommonWealth REIT common shareholders	($16,452)	($227,466)	$7,738	$14,516	($163,935)	($122)	$2,242	$9,857	($221,664)	($151,958)	$62,999
Net income (loss) available for CommonWealth REIT common shareholders per share - basic and diluted (in dollars per share)	($0.14)	($1.92)	$0.07	$0.15	($1.96)	'	$0.03	$0.12	($1.97)	($1.81)	$0.81
Common distributions declared (in dollars per share)	$0.25	$0.25	$0.25	$0.25	$0.25	$0.50	$0.50	$0.50	$1	$1.75	$2

Selected_Quarterly_Financial_D3

Selected Quarterly Financial Data (Unaudited) (Details 2) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Total revenues	$198,419	$198,283	$246,181	$242,653	$231,957	$222,632	$217,346	$209,970	$885,536	$881,905	$741,344
Previously reported	'	'	'	'	'	'	'	'	'	'	'
Total revenues	'	201,741	274,766	275,048	264,692	255,225	249,797	243,378	'	'	'
Revenues from properties reclassified (to) from discontinued operations	'	($3,458)	($28,585)	($32,395)	($32,735)	($32,593)	($32,451)	($33,408)	'	'	'

SCHEDULE_II_VALUATION_AND_QUAL1

SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) (Allowance for doubtful accounts, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts	'	'	'
Movement in valuation and qualifying accounts	'	'	'
Balance at Beginning of Period	$9,962	$12,575	$12,550
Charged to costs and expenses	818	504	2,236
Deductions	-2,895	-3,117	-2,211
Balance at End of Period	$7,885	$9,962	$12,575

SCHEDULE_III_REAL_ESTATE_AND_A1

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	$914,510	'	'	'
Initial Cost to Company	'	'	'	'
Land	709,968	'	'	'
Buildings and Equipment	4,319,098	'	'	'
Costs Capitalized Subsequent to Acquisition	553,308	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Impairment/Write Downs	-45,209	'	'	'
Land	699,135	'	'	'
Buildings and Improvements	4,838,030	'	'	'
Total	5,537,165	7,829,409	7,244,232	6,357,258
Accumulated Depreciation	895,059	1,007,606	934,170	850,261
2501 20th Place South, Birmingham, AL \| CBD	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	11,241	'	'	'
Initial Cost to Company	'	'	'	'
Land	4,000	'	'	'
Buildings and Equipment	19,604	'	'	'
Costs Capitalized Subsequent to Acquisition	475	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	4,002	'	'	'
Buildings and Improvements	20,077	'	'	'
Total	24,079	'	'	'
Accumulated Depreciation	3,579	'	'	'
420 20th Street North, Birmingham, AL \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,740	'	'	'
Buildings and Equipment	49,565	'	'	'
Costs Capitalized Subsequent to Acquisition	4,213	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,740	'	'	'
Buildings and Improvements	53,778	'	'	'
Total	55,518	'	'	'
Accumulated Depreciation	3,206	'	'	'
Inverness Center, Birmingham, AL \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	8,525	'	'	'
Buildings and Equipment	38,367	'	'	'
Costs Capitalized Subsequent to Acquisition	3,506	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	8,525	'	'	'
Buildings and Improvements	41,873	'	'	'
Total	50,398	'	'	'
Accumulated Depreciation	3,827	'	'	'
785 Schilinger Road South, Mobile, AL \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,540	'	'	'
Buildings and Equipment	9,732	'	'	'
Costs Capitalized Subsequent to Acquisition	-3	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,540	'	'	'
Buildings and Improvements	9,729	'	'	'
Total	11,269	'	'	'
Accumulated Depreciation	1,503	'	'	'
Arizona Center, Phoenix, AZ \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	22,614	'	'	'
Buildings and Equipment	64,105	'	'	'
Costs Capitalized Subsequent to Acquisition	5,485	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	22,614	'	'	'
Buildings and Improvements	69,590	'	'	'
Total	92,204	'	'	'
Accumulated Depreciation	4,782	'	'	'
4 South 84th Avenue, Tolleson, AZ \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,257	'	'	'
Buildings and Equipment	9,210	'	'	'
Costs Capitalized Subsequent to Acquisition	696	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,257	'	'	'
Buildings and Improvements	9,906	'	'	'
Total	11,163	'	'	'
Accumulated Depreciation	2,392	'	'	'
One South Church Avenue, Tucson, AZ \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,261	'	'	'
Buildings and Equipment	26,357	'	'	'
Costs Capitalized Subsequent to Acquisition	2,728	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,261	'	'	'
Buildings and Improvements	29,085	'	'	'
Total	32,346	'	'	'
Accumulated Depreciation	8,214	'	'	'
Parkshore Plaza, Folsom, CA \| Suburban property	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	43,266	'	'	'
Initial Cost to Company	'	'	'	'
Land	4,370	'	'	'
Buildings and Equipment	41,749	'	'	'
Costs Capitalized Subsequent to Acquisition	371	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	4,370	'	'	'
Buildings and Improvements	42,120	'	'	'
Total	46,490	'	'	'
Accumulated Depreciation	2,669	'	'	'
Leased Land, Gonzalez, CA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	18,941	'	'	'
Buildings and Equipment	9,060	'	'	'
Costs Capitalized Subsequent to Acquisition	3,822	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	18,939	'	'	'
Buildings and Improvements	12,884	'	'	'
Total	31,823	'	'	'
Accumulated Depreciation	1,689	'	'	'
Sky Park Centre, San Diego, CA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	936	'	'	'
Buildings and Equipment	8,094	'	'	'
Costs Capitalized Subsequent to Acquisition	756	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	935	'	'	'
Buildings and Improvements	8,851	'	'	'
Total	9,786	'	'	'
Accumulated Depreciation	2,751	'	'	'
Sorrento Valley Business Park, San Diego, CA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,425	'	'	'
Buildings and Equipment	12,842	'	'	'
Costs Capitalized Subsequent to Acquisition	3,316	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,425	'	'	'
Buildings and Improvements	16,158	'	'	'
Total	17,583	'	'	'
Accumulated Depreciation	6,340	'	'	'
1921 E. Alton Avenue, Santa Ana, CA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,363	'	'	'
Buildings and Equipment	10,158	'	'	'
Costs Capitalized Subsequent to Acquisition	-3	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,362	'	'	'
Buildings and Improvements	10,156	'	'	'
Total	11,518	'	'	'
Accumulated Depreciation	2,627	'	'	'
9110 East Nichols Avenue, Centennial, CO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,708	'	'	'
Buildings and Equipment	14,616	'	'	'
Costs Capitalized Subsequent to Acquisition	3,960	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,707	'	'	'
Buildings and Improvements	18,577	'	'	'
Total	20,284	'	'	'
Accumulated Depreciation	5,040	'	'	'
7450 Campus Drive, Colorado Springs, CO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,250	'	'	'
Buildings and Equipment	7,982	'	'	'
Costs Capitalized Subsequent to Acquisition	249	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,250	'	'	'
Buildings and Improvements	8,231	'	'	'
Total	9,481	'	'	'
Accumulated Depreciation	733	'	'	'
1225 Seventeenth Street, Denver, CO \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	22,400	'	'	'
Buildings and Equipment	110,090	'	'	'
Costs Capitalized Subsequent to Acquisition	10,705	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	22,400	'	'	'
Buildings and Improvements	120,795	'	'	'
Total	143,195	'	'	'
Accumulated Depreciation	13,730	'	'	'
5073, 5075, & 5085 S. Syracuse Street, Denver, CO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	4,720	'	'	'
Buildings and Equipment	58,890	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	4,720	'	'	'
Buildings and Improvements	58,890	'	'	'
Total	63,610	'	'	'
Accumulated Depreciation	5,398	'	'	'
1601 Dry Creek Drive, Longmont, CO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,714	'	'	'
Buildings and Equipment	24,397	'	'	'
Costs Capitalized Subsequent to Acquisition	4,156	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,715	'	'	'
Buildings and Improvements	28,552	'	'	'
Total	32,267	'	'	'
Accumulated Depreciation	7,025	'	'	'
129 Worthington Ridge Road, Berlin, CT \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,770	'	'	'
Buildings and Equipment	8,409	'	'	'
Costs Capitalized Subsequent to Acquisition	1,161	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Impairment/Write Downs	-7,088	'	'	'
Land	1,114	'	'	'
Buildings and Improvements	4,138	'	'	'
Total	5,252	'	'	'
Accumulated Depreciation	451	'	'	'
97 Newberry Road, East Windsor, CT \| Suburban property	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	7,240	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,960	'	'	'
Buildings and Equipment	12,360	'	'	'
Costs Capitalized Subsequent to Acquisition	30	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,943	'	'	'
Buildings and Improvements	12,407	'	'	'
Total	15,350	'	'	'
Accumulated Depreciation	2,245	'	'	'
185 Asylum Street, Hartford, CT \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	15,930	'	'	'
Buildings and Equipment	60,312	'	'	'
Costs Capitalized Subsequent to Acquisition	820	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	15,930	'	'	'
Buildings and Improvements	61,132	'	'	'
Total	77,062	'	'	'
Accumulated Depreciation	2,661	'	'	'
599 Research Parkway, Meriden, CT \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	768	'	'	'
Buildings and Equipment	6,164	'	'	'
Costs Capitalized Subsequent to Acquisition	1,160	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	768	'	'	'
Buildings and Improvements	7,324	'	'	'
Total	8,092	'	'	'
Accumulated Depreciation	1,684	'	'	'
33 Stiles Lane, North Haven, CT \| Suburban property	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	3,456	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,090	'	'	'
Buildings and Equipment	9,141	'	'	'
Costs Capitalized Subsequent to Acquisition	216	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,091	'	'	'
Buildings and Improvements	9,356	'	'	'
Total	11,447	'	'	'
Accumulated Depreciation	1,689	'	'	'
181 Marsh Hill Road, Orange, CT \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,270	'	'	'
Buildings and Equipment	7,943	'	'	'
Costs Capitalized Subsequent to Acquisition	419	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,271	'	'	'
Buildings and Improvements	8,361	'	'	'
Total	10,632	'	'	'
Accumulated Depreciation	1,446	'	'	'
50 Barnes Industrial Road North, Wallingford, CT \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,300	'	'	'
Buildings and Equipment	8,621	'	'	'
Costs Capitalized Subsequent to Acquisition	2,937	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,301	'	'	'
Buildings and Improvements	11,557	'	'	'
Total	13,858	'	'	'
Accumulated Depreciation	2,071	'	'	'
5-9 Barnes Industrial Road, Wallingford, CT \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	740	'	'	'
Buildings and Equipment	2,552	'	'	'
Costs Capitalized Subsequent to Acquisition	37	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	741	'	'	'
Buildings and Improvements	2,588	'	'	'
Total	3,329	'	'	'
Accumulated Depreciation	475	'	'	'
860 North Main Street, Wallingford, CT \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	680	'	'	'
Buildings and Equipment	3,144	'	'	'
Costs Capitalized Subsequent to Acquisition	990	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	680	'	'	'
Buildings and Improvements	4,134	'	'	'
Total	4,814	'	'	'
Accumulated Depreciation	813	'	'	'
One Barnes Industrial Road South, Wallingford, CT \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	800	'	'	'
Buildings and Equipment	2,251	'	'	'
Costs Capitalized Subsequent to Acquisition	5	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	800	'	'	'
Buildings and Improvements	2,256	'	'	'
Total	3,056	'	'	'
Accumulated Depreciation	409	'	'	'
100 Northfield Drive, Windsor, CT \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,376	'	'	'
Buildings and Equipment	11,212	'	'	'
Costs Capitalized Subsequent to Acquisition	2,911	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,376	'	'	'
Buildings and Improvements	14,123	'	'	'
Total	15,499	'	'	'
Accumulated Depreciation	4,039	'	'	'
1250 H Street, NW, Washington, DC \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	5,975	'	'	'
Buildings and Equipment	53,778	'	'	'
Costs Capitalized Subsequent to Acquisition	4,560	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	5,975	'	'	'
Buildings and Improvements	58,338	'	'	'
Total	64,313	'	'	'
Accumulated Depreciation	22,313	'	'	'
Georgetown-Green and Harris Buildings, Washington, DC \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	24,000	'	'	'
Buildings and Equipment	35,979	'	'	'
Costs Capitalized Subsequent to Acquisition	21	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	24,000	'	'	'
Buildings and Improvements	36,000	'	'	'
Total	60,000	'	'	'
Accumulated Depreciation	3,897	'	'	'
802 Delaware Avenue, Wilmington, DE \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	4,409	'	'	'
Buildings and Equipment	39,681	'	'	'
Costs Capitalized Subsequent to Acquisition	10,320	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	4,413	'	'	'
Buildings and Improvements	49,997	'	'	'
Total	54,410	'	'	'
Accumulated Depreciation	20,423	'	'	'
6600 North Military Trail, Boca Raton, FL \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	15,900	'	'	'
Buildings and Equipment	129,790	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	15,900	'	'	'
Buildings and Improvements	129,790	'	'	'
Total	145,690	'	'	'
Accumulated Depreciation	9,734	'	'	'
225 Water Street, Jacksonville, FL \| CBD	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	38,693	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,480	'	'	'
Buildings and Equipment	43,770	'	'	'
Costs Capitalized Subsequent to Acquisition	3,020	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,480	'	'	'
Buildings and Improvements	46,790	'	'	'
Total	48,270	'	'	'
Accumulated Depreciation	6,280	'	'	'
The Exchange, Atlanta, GA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,576	'	'	'
Buildings and Equipment	13,134	'	'	'
Costs Capitalized Subsequent to Acquisition	3,195	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,577	'	'	'
Buildings and Improvements	16,328	'	'	'
Total	17,905	'	'	'
Accumulated Depreciation	3,822	'	'	'
9040 Roswell Road, Atlanta, GA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,459	'	'	'
Buildings and Equipment	18,549	'	'	'
Costs Capitalized Subsequent to Acquisition	2,153	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,463	'	'	'
Buildings and Improvements	20,698	'	'	'
Total	23,161	'	'	'
Accumulated Depreciation	4,801	'	'	'
Executive Park, Atlanta, GA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	13,729	'	'	'
Buildings and Equipment	78,032	'	'	'
Costs Capitalized Subsequent to Acquisition	5,567	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Impairment/Write Downs	-34,109	'	'	'
Land	13,727	'	'	'
Buildings and Improvements	49,492	'	'	'
Total	63,219	'	'	'
Accumulated Depreciation	12,434	'	'	'
3920 Arkwright Road, Macon, GA \| Suburban property	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	11,976	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,674	'	'	'
Buildings and Equipment	19,311	'	'	'
Costs Capitalized Subsequent to Acquisition	2,401	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,675	'	'	'
Buildings and Improvements	21,711	'	'	'
Total	24,386	'	'	'
Accumulated Depreciation	4,178	'	'	'
1775 West Oak Commons Court, Marietta, GA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,190	'	'	'
Buildings and Equipment	6,586	'	'	'
Costs Capitalized Subsequent to Acquisition	985	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,190	'	'	'
Buildings and Improvements	7,571	'	'	'
Total	9,761	'	'	'
Accumulated Depreciation	1,110	'	'	'
633 Ahua Street, Honolulu, HI \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,256	'	'	'
Buildings and Equipment	3	'	'	'
Costs Capitalized Subsequent to Acquisition	18,047	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,256	'	'	'
Buildings and Improvements	18,050	'	'	'
Total	19,306	'	'	'
Accumulated Depreciation	2,945	'	'	'
905 Meridian Lake Drive, Aurora, IL \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,740	'	'	'
Buildings and Equipment	13,586	'	'	'
Costs Capitalized Subsequent to Acquisition	52	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,740	'	'	'
Buildings and Improvements	13,638	'	'	'
Total	15,378	'	'	'
Accumulated Depreciation	2,265	'	'	'
1200 Lakeside Drive, Bannockburn, IL \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	5,846	'	'	'
Buildings and Equipment	48,568	'	'	'
Costs Capitalized Subsequent to Acquisition	10,422	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	5,858	'	'	'
Buildings and Improvements	58,978	'	'	'
Total	64,836	'	'	'
Accumulated Depreciation	10,688	'	'	'
Illinois Center, Chicago, IL \| CBD	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	151,364	'	'	'
Initial Cost to Company	'	'	'	'
Land	66,757	'	'	'
Buildings and Equipment	239,143	'	'	'
Costs Capitalized Subsequent to Acquisition	22,347	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	66,757	'	'	'
Buildings and Improvements	261,490	'	'	'
Total	328,247	'	'	'
Accumulated Depreciation	15,082	'	'	'
600 West Chicago Avenue, Chicago, IL \| CBD	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	273,506	'	'	'
Initial Cost to Company	'	'	'	'
Land	34,980	'	'	'
Buildings and Equipment	315,643	'	'	'
Costs Capitalized Subsequent to Acquisition	1,775	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	34,989	'	'	'
Buildings and Improvements	317,409	'	'	'
Total	352,398	'	'	'
Accumulated Depreciation	19,213	'	'	'
8750 Bryn Mawr Avenue, Chicago, IL \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	6,600	'	'	'
Buildings and Equipment	77,764	'	'	'
Costs Capitalized Subsequent to Acquisition	4,292	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	6,600	'	'	'
Buildings and Improvements	82,056	'	'	'
Total	88,656	'	'	'
Accumulated Depreciation	6,652	'	'	'
1955 West Field Court, Lake Forest, IL \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,258	'	'	'
Buildings and Equipment	9,630	'	'	'
Costs Capitalized Subsequent to Acquisition	2,990	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,261	'	'	'
Buildings and Improvements	12,617	'	'	'
Total	13,878	'	'	'
Accumulated Depreciation	2,495	'	'	'
101-115 W. Washington Street, Indianapolis, IN \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	7,495	'	'	'
Buildings and Equipment	60,465	'	'	'
Costs Capitalized Subsequent to Acquisition	20,429	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	7,496	'	'	'
Buildings and Improvements	80,893	'	'	'
Total	88,389	'	'	'
Accumulated Depreciation	18,710	'	'	'
111 Monument Circle, Indianapolis, IN \| CBD	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	120,885	'	'	'
Initial Cost to Company	'	'	'	'
Land	9,670	'	'	'
Buildings and Equipment	158,085	'	'	'
Costs Capitalized Subsequent to Acquisition	1,577	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	9,670	'	'	'
Buildings and Improvements	159,662	'	'	'
Total	169,332	'	'	'
Accumulated Depreciation	4,617	'	'	'
5015 S. Water Circle, Wichita, KS \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,720	'	'	'
Buildings and Equipment	2,029	'	'	'
Costs Capitalized Subsequent to Acquisition	1,124	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,719	'	'	'
Buildings and Improvements	3,154	'	'	'
Total	5,873	'	'	'
Accumulated Depreciation	570	'	'	'
701 Poydras Street, New Orleans, LA \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	9,100	'	'	'
Buildings and Equipment	78,540	'	'	'
Costs Capitalized Subsequent to Acquisition	4,908	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	9,100	'	'	'
Buildings and Improvements	83,448	'	'	'
Total	92,548	'	'	'
Accumulated Depreciation	4,892	'	'	'
109 Brookline Avenue, Boston, MA \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,168	'	'	'
Buildings and Equipment	30,397	'	'	'
Costs Capitalized Subsequent to Acquisition	13,591	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,168	'	'	'
Buildings and Improvements	43,988	'	'	'
Total	47,156	'	'	'
Accumulated Depreciation	18,354	'	'	'
Cabot Business Park Land, Mansfield, MA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,033	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,033	'	'	'
Total	1,033	'	'	'
2300 Crown Colony Drive, Quincy, MA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	774	'	'	'
Buildings and Equipment	5,815	'	'	'
Costs Capitalized Subsequent to Acquisition	1,529	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	779	'	'	'
Buildings and Improvements	7,339	'	'	'
Total	8,118	'	'	'
Accumulated Depreciation	2,073	'	'	'
340 Thompson Road, Webster, MA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	315	'	'	'
Buildings and Equipment	2,834	'	'	'
Costs Capitalized Subsequent to Acquisition	39	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	315	'	'	'
Buildings and Improvements	2,873	'	'	'
Total	3,188	'	'	'
Accumulated Depreciation	1,196	'	'	'
100 South Charles Street, Baltimore, MD \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Buildings and Equipment	12,430	'	'	'
Costs Capitalized Subsequent to Acquisition	3,840	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Buildings and Improvements	16,270	'	'	'
Total	16,270	'	'	'
Accumulated Depreciation	6,069	'	'	'
111 Market Place, Baltimore, MD \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	6,328	'	'	'
Buildings and Equipment	54,645	'	'	'
Costs Capitalized Subsequent to Acquisition	14,343	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	6,328	'	'	'
Buildings and Improvements	68,988	'	'	'
Total	75,316	'	'	'
Accumulated Depreciation	19,409	'	'	'
25 S. Charles Street, Baltimore, MD \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,830	'	'	'
Buildings and Equipment	22,996	'	'	'
Costs Capitalized Subsequent to Acquisition	12,672	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,830	'	'	'
Buildings and Improvements	35,668	'	'	'
Total	38,498	'	'	'
Accumulated Depreciation	9,839	'	'	'
820 W. Diamond, Gaithersburg, MD \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	4,381	'	'	'
Buildings and Equipment	18,798	'	'	'
Costs Capitalized Subsequent to Acquisition	9,959	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	4,461	'	'	'
Buildings and Improvements	28,677	'	'	'
Total	33,138	'	'	'
Accumulated Depreciation	9,245	'	'	'
6710 Oxon Hill, Oxon Hill, MD \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,181	'	'	'
Buildings and Equipment	13,653	'	'	'
Costs Capitalized Subsequent to Acquisition	2,845	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,131	'	'	'
Buildings and Improvements	16,548	'	'	'
Total	19,679	'	'	'
Accumulated Depreciation	6,668	'	'	'
Danac Stiles Business Park, Rockville, MD \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	7,638	'	'	'
Buildings and Equipment	62,572	'	'	'
Costs Capitalized Subsequent to Acquisition	5,077	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	7,639	'	'	'
Buildings and Improvements	67,648	'	'	'
Total	75,287	'	'	'
Accumulated Depreciation	14,982	'	'	'
East Eisenhower Parkway, Ann Arbor, MI \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	6,760	'	'	'
Buildings and Equipment	46,988	'	'	'
Costs Capitalized Subsequent to Acquisition	982	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	6,760	'	'	'
Buildings and Improvements	47,970	'	'	'
Total	54,730	'	'	'
Accumulated Depreciation	4,252	'	'	'
2250 Pilot Knob Road, Mendota Heights, MN \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	533	'	'	'
Buildings and Equipment	4,795	'	'	'
Costs Capitalized Subsequent to Acquisition	1,103	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	533	'	'	'
Buildings and Improvements	5,898	'	'	'
Total	6,431	'	'	'
Accumulated Depreciation	2,179	'	'	'
9800 Shelard Parkway, Plymouth, MN \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	563	'	'	'
Buildings and Equipment	5,064	'	'	'
Costs Capitalized Subsequent to Acquisition	1,022	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	563	'	'	'
Buildings and Improvements	6,086	'	'	'
Total	6,649	'	'	'
Accumulated Depreciation	2,367	'	'	'
Rosedale Corporate Plaza, Roseville, MN \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,860	'	'	'
Buildings and Equipment	16,750	'	'	'
Costs Capitalized Subsequent to Acquisition	8,949	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,859	'	'	'
Buildings and Improvements	25,700	'	'	'
Total	27,559	'	'	'
Accumulated Depreciation	7,541	'	'	'
411 Farwell Avenue, South St. Paul, MN \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,303	'	'	'
Buildings and Equipment	10,451	'	'	'
Costs Capitalized Subsequent to Acquisition	3,949	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,304	'	'	'
Buildings and Improvements	14,399	'	'	'
Total	15,703	'	'	'
Accumulated Depreciation	2,613	'	'	'
6200 Glenn Carlson Drive, St. Cloud, MN \| Suburban property	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	7,987	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,950	'	'	'
Buildings and Equipment	13,803	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,950	'	'	'
Buildings and Improvements	13,803	'	'	'
Total	15,753	'	'	'
Accumulated Depreciation	1,467	'	'	'
1000 Shelard Parkway, St. Louis Park, MN \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	695	'	'	'
Buildings and Equipment	6,254	'	'	'
Costs Capitalized Subsequent to Acquisition	2,004	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	695	'	'	'
Buildings and Improvements	8,258	'	'	'
Total	8,953	'	'	'
Accumulated Depreciation	3,018	'	'	'
525 Park Street, St. Paul, MN \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	696	'	'	'
Buildings and Equipment	6,263	'	'	'
Costs Capitalized Subsequent to Acquisition	1,669	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	695	'	'	'
Buildings and Improvements	7,933	'	'	'
Total	8,628	'	'	'
Accumulated Depreciation	3,150	'	'	'
1900 Meyer Drury Drive, Arnold, MO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	834	'	'	'
Buildings and Equipment	7,302	'	'	'
Costs Capitalized Subsequent to Acquisition	475	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	838	'	'	'
Buildings and Improvements	7,773	'	'	'
Total	8,611	'	'	'
Accumulated Depreciation	1,830	'	'	'
4700 Belleview Avenue, Kansas City, MO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,165	'	'	'
Buildings and Equipment	3,097	'	'	'
Costs Capitalized Subsequent to Acquisition	2,110	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,165	'	'	'
Buildings and Improvements	5,207	'	'	'
Total	6,372	'	'	'
Accumulated Depreciation	601	'	'	'
131-165 West Ninth Street, N. Kansas City, MO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	494	'	'	'
Buildings and Equipment	959	'	'	'
Costs Capitalized Subsequent to Acquisition	300	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	494	'	'	'
Buildings and Improvements	1,259	'	'	'
Total	1,753	'	'	'
Accumulated Depreciation	165	'	'	'
12655 Olive Boulevard, St. Louis, MO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	4,800	'	'	'
Buildings and Equipment	8,020	'	'	'
Costs Capitalized Subsequent to Acquisition	1,690	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	4,801	'	'	'
Buildings and Improvements	9,709	'	'	'
Total	14,510	'	'	'
Accumulated Depreciation	1,633	'	'	'
1285 Fern Ridge Parkway, St. Louis, MO \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	903	'	'	'
Buildings and Equipment	7,602	'	'	'
Costs Capitalized Subsequent to Acquisition	1,110	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	903	'	'	'
Buildings and Improvements	8,712	'	'	'
Total	9,615	'	'	'
Accumulated Depreciation	2,162	'	'	'
300 North Greene Street, Greensboro, NC \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,070	'	'	'
Buildings and Equipment	37,073	'	'	'
Costs Capitalized Subsequent to Acquisition	1,184	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,070	'	'	'
Buildings and Improvements	38,257	'	'	'
Total	40,327	'	'	'
Accumulated Depreciation	3,228	'	'	'
111 River Street, Hoboken, NJ \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Buildings and Equipment	134,199	'	'	'
Costs Capitalized Subsequent to Acquisition	201	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Buildings and Improvements	134,400	'	'	'
Total	134,400	'	'	'
Accumulated Depreciation	14,836	'	'	'
5 Paragon Drive, Montvale, NJ \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,650	'	'	'
Buildings and Equipment	13,725	'	'	'
Costs Capitalized Subsequent to Acquisition	309	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,650	'	'	'
Buildings and Improvements	14,034	'	'	'
Total	17,684	'	'	'
Accumulated Depreciation	1,010	'	'	'
One Park Square, Albuquerque, NM \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,582	'	'	'
Buildings and Equipment	21,532	'	'	'
Costs Capitalized Subsequent to Acquisition	4,668	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,582	'	'	'
Buildings and Improvements	26,200	'	'	'
Total	28,782	'	'	'
Accumulated Depreciation	7,492	'	'	'
North Point Office Complex, Cleveland, OH \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	12,000	'	'	'
Buildings and Equipment	94,448	'	'	'
Costs Capitalized Subsequent to Acquisition	14,954	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	12,000	'	'	'
Buildings and Improvements	109,402	'	'	'
Total	121,402	'	'	'
Accumulated Depreciation	15,380	'	'	'
401 Vine Street, Delmont, PA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,575	'	'	'
Buildings and Equipment	5,542	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,575	'	'	'
Buildings and Improvements	5,542	'	'	'
Total	7,117	'	'	'
Accumulated Depreciation	853	'	'	'
515 Pennsylvania Avenue, Fort Washington, PA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,872	'	'	'
Buildings and Equipment	8,816	'	'	'
Costs Capitalized Subsequent to Acquisition	4,291	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,872	'	'	'
Buildings and Improvements	13,107	'	'	'
Total	14,979	'	'	'
Accumulated Depreciation	4,331	'	'	'
443 Gulph Road, King of Prussia, PA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	634	'	'	'
Buildings and Equipment	3,251	'	'	'
Costs Capitalized Subsequent to Acquisition	1,070	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	634	'	'	'
Buildings and Improvements	4,321	'	'	'
Total	4,955	'	'	'
Accumulated Depreciation	1,932	'	'	'
4350 Northern Pike, Monroeville, PA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	6,558	'	'	'
Buildings and Equipment	51,775	'	'	'
Costs Capitalized Subsequent to Acquisition	16,895	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	6,564	'	'	'
Buildings and Improvements	68,664	'	'	'
Total	75,228	'	'	'
Accumulated Depreciation	13,106	'	'	'
Cherrington Corporate Center, Moon Township, PA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	11,369	'	'	'
Buildings and Equipment	39,892	'	'	'
Costs Capitalized Subsequent to Acquisition	18,008	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	12,192	'	'	'
Buildings and Improvements	57,077	'	'	'
Total	69,269	'	'	'
Accumulated Depreciation	17,405	'	'	'
1500 Market Street, Philadelphia, PA \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	18,758	'	'	'
Buildings and Equipment	167,487	'	'	'
Costs Capitalized Subsequent to Acquisition	89,351	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	18,758	'	'	'
Buildings and Improvements	256,838	'	'	'
Total	275,596	'	'	'
Accumulated Depreciation	63,340	'	'	'
1525 Locust Street, Philadelphia, PA \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	931	'	'	'
Buildings and Equipment	8,377	'	'	'
Costs Capitalized Subsequent to Acquisition	1,605	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	930	'	'	'
Buildings and Improvements	9,983	'	'	'
Total	10,913	'	'	'
Accumulated Depreciation	3,341	'	'	'
1600 Market Street, Philadelphia, PA \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,462	'	'	'
Buildings and Equipment	111,946	'	'	'
Costs Capitalized Subsequent to Acquisition	24,590	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,462	'	'	'
Buildings and Improvements	136,536	'	'	'
Total	139,998	'	'	'
Accumulated Depreciation	55,731	'	'	'
1735 Market Street, Philadelphia, PA \| CBD	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	173,247	'	'	'
Initial Cost to Company	'	'	'	'
Land	24,753	'	'	'
Buildings and Equipment	222,775	'	'	'
Costs Capitalized Subsequent to Acquisition	49,206	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	24,747	'	'	'
Buildings and Improvements	271,987	'	'	'
Total	296,734	'	'	'
Accumulated Depreciation	104,277	'	'	'
Foster Plaza, Pittsburgh, PA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	6,168	'	'	'
Buildings and Equipment	51,588	'	'	'
Costs Capitalized Subsequent to Acquisition	13,209	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	6,169	'	'	'
Buildings and Improvements	64,796	'	'	'
Total	70,965	'	'	'
Accumulated Depreciation	13,813	'	'	'
128 Crews Drive, Columbia, SC \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,420	'	'	'
Buildings and Equipment	4,017	'	'	'
Costs Capitalized Subsequent to Acquisition	1,321	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Impairment/Write Downs	-4,012	'	'	'
Land	1,024	'	'	'
Buildings and Improvements	2,722	'	'	'
Total	3,746	'	'	'
Accumulated Depreciation	279	'	'	'
1320 Main Street, Columbia, SC \| CBD	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	41,480	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,660	'	'	'
Buildings and Equipment	53,058	'	'	'
Costs Capitalized Subsequent to Acquisition	25	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,660	'	'	'
Buildings and Improvements	53,083	'	'	'
Total	54,743	'	'	'
Accumulated Depreciation	1,661	'	'	'
111 Southchase Boulevard, Fountain Inn, SC \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	520	'	'	'
Buildings and Equipment	6,822	'	'	'
Costs Capitalized Subsequent to Acquisition	967	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	520	'	'	'
Buildings and Improvements	7,789	'	'	'
Total	8,309	'	'	'
Accumulated Depreciation	1,195	'	'	'
1043 Global Avenue, Graniteville, SC \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	720	'	'	'
Buildings and Equipment	15,552	'	'	'
Costs Capitalized Subsequent to Acquisition	358	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	720	'	'	'
Buildings and Improvements	15,910	'	'	'
Total	16,630	'	'	'
Accumulated Depreciation	2,603	'	'	'
633 Frazier Drive, Franklin, TN \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	5,800	'	'	'
Buildings and Equipment	13,190	'	'	'
Costs Capitalized Subsequent to Acquisition	-10	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	5,800	'	'	'
Buildings and Improvements	13,180	'	'	'
Total	18,980	'	'	'
Accumulated Depreciation	2,052	'	'	'
775 Ridge Lake Boulevard, Memphis, TN \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,113	'	'	'
Buildings and Equipment	18,201	'	'	'
Costs Capitalized Subsequent to Acquisition	499	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,114	'	'	'
Buildings and Improvements	18,699	'	'	'
Total	20,813	'	'	'
Accumulated Depreciation	4,539	'	'	'
1601 Rio Grande Street, Austin, TX \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	688	'	'	'
Buildings and Equipment	6,192	'	'	'
Costs Capitalized Subsequent to Acquisition	1,160	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	697	'	'	'
Buildings and Improvements	7,343	'	'	'
Total	8,040	'	'	'
Accumulated Depreciation	2,637	'	'	'
206 East 9th Street, Austin, TX \| CBD	'	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'	'
Encumbrances	30,169	'	'	'
Initial Cost to Company	'	'	'	'
Land	7,900	'	'	'
Buildings and Equipment	38,533	'	'	'
Costs Capitalized Subsequent to Acquisition	1,201	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	7,900	'	'	'
Buildings and Improvements	39,734	'	'	'
Total	47,634	'	'	'
Accumulated Depreciation	1,531	'	'	'
4515 Seton Center Parkway, Austin, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,038	'	'	'
Buildings and Equipment	18,338	'	'	'
Costs Capitalized Subsequent to Acquisition	2,779	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,037	'	'	'
Buildings and Improvements	21,118	'	'	'
Total	23,155	'	'	'
Accumulated Depreciation	7,785	'	'	'
4516 Seton Center Parkway, Austin, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,028	'	'	'
Buildings and Equipment	18,251	'	'	'
Costs Capitalized Subsequent to Acquisition	2,799	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,027	'	'	'
Buildings and Improvements	21,051	'	'	'
Total	23,078	'	'	'
Accumulated Depreciation	7,779	'	'	'
7800 Shoal Creek Boulevard, Austin, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,731	'	'	'
Buildings and Equipment	14,921	'	'	'
Costs Capitalized Subsequent to Acquisition	3,736	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,731	'	'	'
Buildings and Improvements	18,657	'	'	'
Total	20,388	'	'	'
Accumulated Depreciation	6,279	'	'	'
812 San Antonio Street, Austin, TX \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	626	'	'	'
Buildings and Equipment	5,636	'	'	'
Costs Capitalized Subsequent to Acquisition	2,207	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	621	'	'	'
Buildings and Improvements	7,848	'	'	'
Total	8,469	'	'	'
Accumulated Depreciation	2,535	'	'	'
8701 N Mopac, Austin, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,574	'	'	'
Buildings and Equipment	14,168	'	'	'
Costs Capitalized Subsequent to Acquisition	2,651	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,573	'	'	'
Buildings and Improvements	16,820	'	'	'
Total	18,393	'	'	'
Accumulated Depreciation	5,759	'	'	'
Bridgepoint Parkway, Austin, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	7,784	'	'	'
Buildings and Equipment	70,526	'	'	'
Costs Capitalized Subsequent to Acquisition	9,302	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	7,784	'	'	'
Buildings and Improvements	79,828	'	'	'
Total	87,612	'	'	'
Accumulated Depreciation	32,105	'	'	'
Lakewood on the Park, Austin, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,548	'	'	'
Buildings and Equipment	31,936	'	'	'
Costs Capitalized Subsequent to Acquisition	1,512	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,548	'	'	'
Buildings and Improvements	33,448	'	'	'
Total	36,996	'	'	'
Accumulated Depreciation	12,603	'	'	'
Research Park, Austin, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	15,859	'	'	'
Buildings and Equipment	60,175	'	'	'
Costs Capitalized Subsequent to Acquisition	14,520	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	18,411	'	'	'
Buildings and Improvements	72,143	'	'	'
Total	90,554	'	'	'
Accumulated Depreciation	24,124	'	'	'
9840 Gateway Boulevard North, El Paso, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,700	'	'	'
Buildings and Equipment	9,736	'	'	'
Costs Capitalized Subsequent to Acquisition	-4	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,700	'	'	'
Buildings and Improvements	9,732	'	'	'
Total	11,432	'	'	'
Accumulated Depreciation	1,509	'	'	'
3003 South Expressway 281, Hidalgo, TX \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,480	'	'	'
Buildings and Equipment	15,533	'	'	'
Costs Capitalized Subsequent to Acquisition	-9	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,480	'	'	'
Buildings and Improvements	15,524	'	'	'
Total	17,004	'	'	'
Accumulated Depreciation	2,417	'	'	'
3330 N Washington Boulevard, Arlington, VA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	810	'	'	'
Buildings and Equipment	7,289	'	'	'
Costs Capitalized Subsequent to Acquisition	616	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	811	'	'	'
Buildings and Improvements	7,904	'	'	'
Total	8,715	'	'	'
Accumulated Depreciation	2,898	'	'	'
6160 Kempsville Circle, Norfolk, VA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,273	'	'	'
Buildings and Equipment	11,083	'	'	'
Costs Capitalized Subsequent to Acquisition	4,226	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,273	'	'	'
Buildings and Improvements	15,309	'	'	'
Total	16,582	'	'	'
Accumulated Depreciation	5,221	'	'	'
Thunderbolt Place, Chantilly, VA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,374	'	'	'
Buildings and Equipment	12,369	'	'	'
Costs Capitalized Subsequent to Acquisition	941	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,375	'	'	'
Buildings and Improvements	13,309	'	'	'
Total	14,684	'	'	'
Accumulated Depreciation	4,919	'	'	'
448 Viking Drive, Virginia Beach, VA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	682	'	'	'
Buildings and Equipment	5,431	'	'	'
Costs Capitalized Subsequent to Acquisition	1,429	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	686	'	'	'
Buildings and Improvements	6,856	'	'	'
Total	7,542	'	'	'
Accumulated Depreciation	1,425	'	'	'
333 108th Avenue NE, Bellevue, WA \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	14,400	'	'	'
Buildings and Equipment	136,412	'	'	'
Costs Capitalized Subsequent to Acquisition	1,666	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	14,400	'	'	'
Buildings and Improvements	138,078	'	'	'
Total	152,478	'	'	'
Accumulated Depreciation	14,798	'	'	'
600 108th Avenue NE, Bellevue, WA \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,555	'	'	'
Buildings and Equipment	30,244	'	'	'
Costs Capitalized Subsequent to Acquisition	8,953	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,555	'	'	'
Buildings and Improvements	39,197	'	'	'
Total	42,752	'	'	'
Accumulated Depreciation	8,637	'	'	'
1331 North Center Parkway, Kennewick, WA \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	1,850	'	'	'
Buildings and Equipment	7,339	'	'	'
Costs Capitalized Subsequent to Acquisition	-2	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,850	'	'	'
Buildings and Improvements	7,337	'	'	'
Total	9,187	'	'	'
Accumulated Depreciation	1,139	'	'	'
100 East Wisconsin Avenue, Milwaukee, WI \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,150	'	'	'
Buildings and Equipment	72,113	'	'	'
Costs Capitalized Subsequent to Acquisition	4,592	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,150	'	'	'
Buildings and Improvements	76,705	'	'	'
Total	79,855	'	'	'
Accumulated Depreciation	6,676	'	'	'
111 East Kilbourn Avenue, Milwaukee, WI \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,400	'	'	'
Buildings and Equipment	47,562	'	'	'
Costs Capitalized Subsequent to Acquisition	4,897	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,400	'	'	'
Buildings and Improvements	52,459	'	'	'
Total	54,859	'	'	'
Accumulated Depreciation	7,481	'	'	'
7 Modal Crescent, Canning Vale, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	9,806	'	'	'
Buildings and Equipment	3,925	'	'	'
Costs Capitalized Subsequent to Acquisition	641	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	8,915	'	'	'
Buildings and Improvements	5,457	'	'	'
Total	14,372	'	'	'
Accumulated Depreciation	358	'	'	'
71-93 Whiteside Road, Clayton, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	9,757	'	'	'
Buildings and Equipment	8,495	'	'	'
Costs Capitalized Subsequent to Acquisition	-1,658	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	8,870	'	'	'
Buildings and Improvements	7,724	'	'	'
Total	16,594	'	'	'
Accumulated Depreciation	624	'	'	'
9-13 Titanium Court, Crestmead, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	3,400	'	'	'
Buildings and Equipment	3,185	'	'	'
Costs Capitalized Subsequent to Acquisition	-598	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,091	'	'	'
Buildings and Improvements	2,896	'	'	'
Total	5,987	'	'	'
Accumulated Depreciation	234	'	'	'
16 Rodborough Road, Frenchs Forest, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	7,355	'	'	'
Buildings and Equipment	9,498	'	'	'
Costs Capitalized Subsequent to Acquisition	-1,069	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	6,686	'	'	'
Buildings and Improvements	9,098	'	'	'
Total	15,784	'	'	'
Accumulated Depreciation	710	'	'	'
22 Rodborough Road, Frenchs Forest, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,452	'	'	'
Buildings and Equipment	3,923	'	'	'
Costs Capitalized Subsequent to Acquisition	320	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	2,229	'	'	'
Buildings and Improvements	4,466	'	'	'
Total	6,695	'	'	'
Accumulated Depreciation	343	'	'	'
127-161 Cherry Lane, Laverton North, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	4,266	'	'	'
Buildings and Equipment	5,220	'	'	'
Costs Capitalized Subsequent to Acquisition	-862	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,878	'	'	'
Buildings and Improvements	4,746	'	'	'
Total	8,624	'	'	'
Accumulated Depreciation	384	'	'	'
310-314 Invermay Road, Mowbray, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	431	'	'	'
Buildings and Equipment	535	'	'	'
Costs Capitalized Subsequent to Acquisition	-87	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	392	'	'	'
Buildings and Improvements	487	'	'	'
Total	879	'	'	'
Accumulated Depreciation	39	'	'	'
253-293 George Town Road, Rocherlea, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	2,108	'	'	'
Buildings and Equipment	1,331	'	'	'
Costs Capitalized Subsequent to Acquisition	-312	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	1,917	'	'	'
Buildings and Improvements	1,210	'	'	'
Total	3,127	'	'	'
Accumulated Depreciation	98	'	'	'
310-320 Pitt Street, Sydney, Australia \| CBD	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	63,271	'	'	'
Buildings and Equipment	104,588	'	'	'
Costs Capitalized Subsequent to Acquisition	-18,524	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	56,610	'	'	'
Buildings and Improvements	92,725	'	'	'
Total	149,335	'	'	'
Accumulated Depreciation	7,370	'	'	'
44-46 Mandarin Street, Villawood, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	6,374	'	'	'
Buildings and Equipment	8,179	'	'	'
Costs Capitalized Subsequent to Acquisition	-556	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	5,795	'	'	'
Buildings and Improvements	8,202	'	'	'
Total	13,997	'	'	'
Accumulated Depreciation	613	'	'	'
19 Leadership Way, Wangara, Australia \| Suburban property	'	'	'	'
Initial Cost to Company	'	'	'	'
Land	4,217	'	'	'
Buildings and Equipment	2,685	'	'	'
Costs Capitalized Subsequent to Acquisition	-421	'	'	'
Gross amount carried at the end of the period	'	'	'	'
Land	3,833	'	'	'
Buildings and Improvements	2,648	'	'	'
Total	6,481	'	'	'
Accumulated Depreciation	$203	'	'	'

SCHEDULE_III_REAL_ESTATE_AND_A2

SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Real Estate Properties	'	'	'
Balance at the beginning of the year	$7,829,409,000	$7,244,232,000	$6,357,258,000
Additions	231,485,000	1,041,655,000	1,074,010,000
Loss on asset impairment	-384,141,000	-242,497,000	'
Deconsolidation of SIR	-1,446,781,000	'	'
Properties reclassified to discontinued operations	-552,024,000	-174,562,000	42,228,000
Disposals	-140,783,000	-39,419,000	-229,264,000
Balance at the end of the year	5,537,165,000	7,829,409,000	7,244,232,000
Accumulated Depreciation	'	'	'
Balance at the beginning of the year	1,007,606,000	934,170,000	850,261,000
Additions	176,777,000	188,220,000	166,371,000
Loss on asset impairment	-185,795,000	-73,865,000	'
Deconsolidation of SIR	-56,023,000	'	'
Properties reclassified to discontinued operations	-15,471,000	-10,521,000	3,083,000
Disposals	-32,035,000	-30,398,000	-85,545,000
Balance at the end of the year	895,059,000	1,007,606,000	934,170,000
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'
Aggregate cost of properties for federal income tax purposes	5,642,335,000	'	'
Real estate properties additions due to changes in foreign currency exchange	40,020,000	4,986,000	-333,000
Accumulated depreciation additions due to changes in foreign currency exchange	($1,528,000)	$97,000	($73,000)
Buildings and improvements \| Maximum	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'
Estimated useful lives	'40 years	'	'
Personal property \| Maximum	'	'	'
REAL ESTATE AND ACCUMULATED DEPRECIATION	'	'	'
Estimated useful lives	'12 years	'	'

SCHEDULE_IV_MORTGAGE_LOANS_ON_1

SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE (Details) (USD $)	1 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Jan. 31, 2013	Apr. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE	'	'	'	'	'
Interest Rate (as a percent)	6.00%	6.00%	'	'	'
Face Amount of Mortgage	'	'	$8,107	'	'
Carrying Amount of Mortgage	'	'	8,107	1,419	'
Reconciliation of the carrying amount of mortgage loans at the beginning of the period:	'	'	'	'	'
Balance at the beginning of period	1,419	'	1,419	'	8,183
New mortgage loans	7,688	419	7,688	1,419	'
Collections of principal	'	'	-1,000	'	-8,183
Balance at the end of period	'	'	8,107	1,419	'
Salina, NY	'	'	'	'	'
SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE	'	'	'	'	'
Interest Rate (as a percent)	'	'	6.00%	'	'
Periodic Payment Terms	'	'	419	'	'
Face Amount of Mortgage	'	'	419	'	'
Carrying Amount of Mortgage	'	'	419	'	'
Dearborn, MI	'	'	'	'	'
SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE	'	'	'	'	'
Interest Rate (as a percent)	'	'	6.00%	'	'
Periodic Payment Terms	'	'	7,688	'	'
Face Amount of Mortgage	'	'	7,688	'	'
Carrying Amount of Mortgage	'	'	$7,688	'	'