Tier Reit (TIER) 10-Q 5 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	TIER REIT INC
Entity Central Index Key	1176373
Document Type	10-Q
Document Period End Date	31-Mar-15
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		300,555,965
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Real estate
Land	$249,030	$286,430
Building and improvements, net	1,360,923	1,482,336
Total real estate	1,609,953	1,768,766
Cash and cash equivalents	5,764	31,442
Restricted cash	32,761	35,324
Accounts receivable, net	75,466	83,380
Prepaid expenses and other assets	7,222	7,129
Investments in unconsolidated entities	39,422	39,885
Deferred financing fees, net	10,690	10,783
Lease intangibles, net	77,643	94,690
Other intangible assets, net	2,114	2,144
Assets associated with real estate held for sale	255,130	137,640
Total assets	2,116,165	2,211,183
Liabilities
Notes payable	1,124,475	1,194,085
Accounts payable	1,118	2,790
Payables to related parties	2,257	2,041
Accrued liabilities	65,713	77,375
Acquired below-market leases, net	14,381	16,984
Other liabilities	25,797	21,405
Obligations associated with real estate held for sale	104,457	108,343
Total liabilities	1,338,198	1,423,023
Commitments and contingencies
Series A Convertible Preferred Stock	4,626	4,626
Equity
Preferred stock, $.0001 par value per share; 17,490,000 shares authorized, none outstanding	0	0
Convertible stock, $.0001 par value per share; 1,000 shares authorized, none outstanding	0	0
Common stock, $.0001 par value per share; 382,499,000 shares authorized, 299,406,078 and 299,264,100 shares issued and outstanding at March 31, 2015, and December 31, 2014, respectively	30	30
Additional paid-in capital	2,646,122	2,645,902
Cumulative distributions and net loss attributable to common stockholders	-1,868,447	-1,862,555
Accumulated other comprehensive loss	-5,336	-788
Stockholders' equity	772,369	782,589
Noncontrolling interests	972	945
Total equity	773,341	783,534
Total liabilities and equity	$2,116,165	$2,211,183

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, shares authorized	17,490,000	17,490,000
Preferred stock, shares outstanding	0	0
Convertible stock, par value (in dollars per share)	$0.00	$0.00
Convertible stock, shares authorized	1,000	1,000
Convertible stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	382,499,000	382,499,000
Common stock, shares issued	299,406,078	299,264,100
Common stock, shares outstanding	299,406,078	299,264,100

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations and Comprehensive Loss (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Rental revenue	$74,047	$68,298
Expenses
Property operating expenses	24,244	24,709
Interest expense	15,787	15,847
Real estate taxes	11,419	9,758
Property management fees	2,271	2,063
Asset impairment losses	132	0
General and administrative	6,414	4,695
Depreciation and amortization	30,022	28,161
Total expenses	90,289	85,233
Interest and other income	146	249
Loss on early extinguishment of debt	-36	0
Loss from continuing operations before income taxes and equity in operations of investments	-16,132	-16,686
Benefit (provision) for income taxes	76	-68
Equity in operations of investments	243	88
Loss from continuing operations	-15,813	-16,666
Discontinued operations
Income (loss) from discontinued operations	1,305	-12,991
Gain on sale of discontinued operations	8,606	0
Income (loss) from discontinued operations	9,911	-12,991
Net loss	-5,902	-29,657
Net loss attributable to noncontrolling interests
Noncontrolling interests in continuing operations	27	24
Noncontrolling interests in discontinued operations	-17	19
Net loss attributable to common stockholders	-5,892	-29,614
Basic and diluted weighted average common shares outstanding (in shares)	299,348,615	299,228,783
Basic and diluted income (loss) per common share:
Continuing operations (in dollars per share)	($0.05)	($0.06)
Discontinued operations (in dollars per share)	$0.03	($0.04)
Basic and diluted loss per common share (in dollars per share)	($0.02)	($0.10)
Net income (loss) attributable to common stockholders:
Continuing operations	-15,786	-16,642
Discontinued operations	9,894	-12,972
Net loss attributable to common stockholders	-5,892	-29,614
Comprehensive loss:
Net loss	-5,902	-29,657
Other comprehensive loss: unrealized gain on interest rate derivatives	-4,556	0
Comprehensive loss	-10,458	-29,657
Comprehensive loss attributable to noncontrolling interests	18	43
Comprehensive loss attributable to common stockholders	($10,440)	($29,614)

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Changes in Equity (USD $)	Total	Common Stock	Additional Paid-in Capital	Cumulative Distributions and Net Loss Attributable to Common Stockholders	Accumulated Other Comprehensive Loss	Noncontrolling Interests
In Thousands, unless otherwise specified
Balance at Dec. 31, 2013	$800,559	$30	$2,646,741	($1,847,039)	$0	$827
Balance (in shares) at Dec. 31, 2013		299,192
Increase (Decrease) in Equity
Net loss	-29,657			-29,614		-43
Unrealized loss on interest rate derivatives	0
Share-based compensation, net (in shares)	72
Share-based compensation, net	212		178			34
Distributions declared	-33					-33
Balance at Mar. 31, 2014	771,081	30	2,646,919	-1,876,653	0	785
Balance (in shares) at Mar. 31, 2014		299,264
Balance at Dec. 31, 2014	783,534	30	2,645,902	-1,862,555	-788	945
Balance (in shares) at Dec. 31, 2014		299,264
Increase (Decrease) in Equity
Net loss	-5,902			-5,892		-10
Unrealized loss on interest rate derivatives	-4,556				-4,548	-8
Share-based compensation, net (in shares)	142
Share-based compensation, net	265		220			45
Balance at Mar. 31, 2015	$773,341	$30	$2,646,122	($1,868,447)	($5,336)	$972
Balance (in shares) at Mar. 31, 2015		299,406

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities
Net loss	($5,902)	($29,657)
Adjustments to reconcile net loss to net cash used in operating activities:
Asset impairment losses	132	8,225
Gain on sale of discontinued operations	-8,606	0
Loss on early extinguishment of debt	36	0
Amortization of restricted shares and units	535	354
Depreciation and amortization	30,022	34,622
Amortization of lease intangibles	-192	67
Amortization of above and below market rent	-1,187	-1,154
Amortization of deferred financing and mark-to-market costs	894	960
Equity in operations of investments	-243	-88
Ownership portion of management and financing fees from unconsolidated companies	105	119
Distributions from investments	174	0
Change in accounts receivable	-1,284	-1,161
Change in prepaid expenses and other assets	-1,161	-1,259
Change in lease commissions	-4,167	-4,272
Change in other lease intangibles	-196	-477
Change in accounts payable	-1,683	-2,178
Change in accrued liabilities	-16,329	-10,026
Change in other liabilities	1,445	-410
Change in payables to related parties	336	-134
Cash used in operating activities	-7,271	-6,469
Cash flows from investing activities
Return of investments	426	360
Capital expenditures for real estate	-16,057	-13,260
Capital expenditures for real estate under development	-1,059	-9,437
Proceeds from sale of discontinued operations	55,276	0
Proceeds from sale of assets	11,515	0
Change in restricted cash	2,563	-1,410
Cash provided by (used in) investing activities	52,664	-23,747
Cash flows from financing activities
Financing costs	-773	-31
Proceeds from notes payable	173,909	8,404
Payments on notes payable	-243,930	-4,509
Payments on capital lease obligations	-7	0
Transfer of common stock	-270	-141
Distributions to noncontrolling interests	0	-33
Cash provided by (used in) financing activities	-71,071	3,690
Net change in cash and cash equivalents	-25,678	-26,526
Cash and cash equivalents at beginning of period	31,442	57,786
Cash and cash equivalents at end of period	$5,764	$31,260

Business

Business	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business	Business
	Organization
	TIER REIT, Inc. is a self-managed, Dallas, Texas-based real estate investment trust focused primarily on providing quality, attractive, well-managed, commercial office properties located in strategic markets throughout the United States. As used herein, “TIER REIT,” “TIER,” the “Company,” “we,” “us” or “our” refers to TIER REIT, Inc. and its subsidiaries unless the context otherwise requires. TIER’s investment strategy is to acquire, develop, and operate a portfolio of best-in-class office properties in select markets across the U.S. that consistently lead the nation in population and office-using employment growth. TIER REIT was incorporated in June 2002 as a Maryland corporation and has elected to be taxed, and currently qualifies, as a real estate investment trust, or REIT, for federal income tax purposes.  As of March 31, 2015, we owned interests in 34 operating office properties (including four properties that were held for sale), one recently developed non-operating office property, and one retail property, located in 17 markets throughout the United States.
	Substantially all of our business is conducted through Tier Operating Partnership LP (“Tier OP”), a Texas limited partnership.  Our wholly-owned subsidiary, Tier GP, Inc., a Delaware corporation, is the sole general partner of Tier OP.  Our direct and indirect wholly-owned subsidiaries, Tier Business Trust, a Maryland business trust, and Tier Partners, LLC, a Delaware limited liability company, are limited partners owning substantially all of Tier OP.
	As we disclosed in a Current Report on Form 8-K filed on March 25, 2015, our board of directors authorized us to pursue a listing of our common stock on a national securities exchange.

Basis_of_Presentation_and_Sign

Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies
	Interim Unaudited Financial Information
	The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and should be read in conjunction with the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2014, which was filed with the Securities and Exchange Commission (“SEC”) on March 11, 2015.  Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been omitted from this report on Form 10-Q pursuant to the rules and regulations of the SEC.
	The results for the interim periods shown in this report are not necessarily indicative of future financial results.  The accompanying condensed consolidated balance sheets as of March 31, 2015, and December 31, 2014, and condensed consolidated statements of operations and comprehensive loss, changes in equity, and cash flows for the periods ended March 31, 2015 and 2014, have not been audited by our independent registered public accounting firm.  In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all adjustments necessary to present fairly our financial position as of March 31, 2015, and December 31, 2014, and our results of operations and our cash flows for the periods ended March 31, 2015 and 2014.  These adjustments are of a normal recurring nature.
	As discussed in Note 3, “New Accounting Pronouncements,” effective January 1, 2015, we adopted the Financial Accounting Standards Board (“FASB”) guidance that changes the criteria for reporting a discontinued operation. This adoption impacts the comparability of our financial statements as disposals of individual operating properties will generally no longer qualify as discontinued operations.
	We have evaluated subsequent events for recognition or disclosure in our condensed consolidated financial statements.
	Summary of Significant Accounting Policies
	Described below are certain of our significant accounting policies. The disclosures regarding several of the policies have been condensed or omitted in accordance with interim reporting regulations specified by Form 10-Q.  Please see our Annual Report on Form 10-K for a complete listing of all of our significant accounting policies.
	Real Estate
	As of March 31, 2015, and December 31, 2014, the cost basis and accumulated depreciation and amortization related to our consolidated real estate properties and related lease intangibles were as follows (in thousands):
							Lease Intangibles
							Assets						Liabilities
										Acquired Above-Market Leases			Acquired Below-Market Leases
			Buildings and Improvements				Other Lease Intangibles
	as of March 31, 2015
	Cost		$	1,895,389			$	181,267		$	4,074		$	(56,404	)
	Less: accumulated depreciation and amortization		(534,466		)		(103,787		)	(3,911		)	42,023
	Net		$	1,360,923			$	77,480		$	163		$	(14,381	)
							Lease Intangibles
							Assets						Liabilities
										Acquired Above-Market Leases			Acquired Below-Market Leases
			Buildings and Improvements				Other Lease Intangibles
	as of December 31, 2014
	Cost		$	2,039,765			$	215,913		$	11,785		$	(59,605	)
	Less: accumulated depreciation and amortization		(557,429		)		(123,242		)	(9,766		)	42,621
	Net		$	1,482,336			$	92,671		$	2,019		$	(16,984	)
	We amortize the value of in-place leases, in-place tenant improvements, and in-place leasing commissions to expense over the initial term of the respective leases.  The tenant relationship values are amortized to expense over the tenants’ respective initial lease terms and any anticipated renewal periods, but in no event does the amortization period for intangible assets or liabilities exceed the remaining depreciable life of the building.  Should a tenant terminate its lease, the unamortized portion of the acquired lease intangibles related to that tenant would be charged to expense.  The estimated remaining average useful lives for acquired lease intangibles range from an ending date of April 2015 to an ending date of December 2030.  Anticipated amortization associated with the acquired lease intangibles for each of the following five years is as follows (in thousands):
	April - December 2015	$	2,375
	2016	$	1,185
	2017	$	579
	2018	$	(145	)
	2019	$	475
	Impairment of Real Estate Related Assets
	For our consolidated real estate assets, we monitor events and changes in circumstances indicating that the carrying amounts of the real estate assets may not be recoverable.  When such events or changes in circumstances are present, we assess potential impairment by comparing estimated future undiscounted cash flows expected to be generated over the life of the asset including its eventual disposition, to the carrying amount of the asset.  In the event that the carrying amount exceeds the estimated future undiscounted cash flows and also exceeds the fair value of the asset, we recognize an impairment loss to adjust the carrying amount of the asset to its estimated fair value. Our process to estimate the fair value of an asset involves using third party broker valuation estimates, bona fide purchase offers or the expected sales price of an executed sales agreement, which would be considered Level 1 or Level 2 assumptions within the fair value hierarchy. To the extent that this type of third party information is unavailable, we estimate projected cash flows and a risk-adjusted rate of return that we believe would be used by a third party market participant in estimating the fair value of an asset. This is considered a Level 3 assumption within the fair value hierarchy. These projected cash flows are prepared internally by the Company’s asset management professionals and are updated quarterly to reflect in place and projected leasing activity, market revenue and expense growth rates, market capitalization rates, discount rates, and changes in economic and other relevant conditions. The Company’s Chief Financial Officer, Chief Investment Officer, and Chief Accounting Officer review these projected cash flows to assure that the valuation is prepared using reasonable inputs and assumptions which are consistent with market data or with assumptions that would be used by a third party market participant and assume the highest and best use of the real estate investment. For the three months ended March 31, 2015 and 2014, we recorded non-cash impairment charges including amounts recognized in discontinued operations totaling approximately $0.1 million and $8.2 million, respectively, related to the impairment of consolidated real estate assets.  The impairment loss recorded in 2015 within continuing operations related to final estimated closing costs incurred in connection with the disposition of One and Two Chestnut Place. The impairment loss recorded in 2014 related to an asset assessed for impairment due to a change in management’s estimate of the intended hold period.
	For our unconsolidated real estate assets, at each reporting date we compare the estimated fair value of our investment to the carrying amount.  An impairment charge is recorded to the extent the fair value of our investment is less than the carrying amount and the decline in value is determined to be other than a temporary decline.  We had no impairment charges related to our investments in unconsolidated entities for the three months ended March 31, 2015 or 2014.
	In evaluating our investments for impairment, management makes several estimates and assumptions, including, but not limited to, the projected date of disposition (the intended hold period) and sales price for each property, the estimated future cash flows of each property during our estimated ownership period, and for unconsolidated investments, the estimated future distributions from the investment.  A change in these estimates and assumptions could result in understating or overstating the carrying amount of our investments which could be material to our financial statements.
	We undergo continuous evaluations of property level performance, credit market conditions, and financing options.  If our assumptions regarding the cash flows expected to result from the use and eventual disposition of our properties decrease or our expected hold periods decrease, we may incur future impairment charges on our real estate related assets.  In addition, we may incur impairment charges on assets classified as held for sale in the future if the carrying amount of the asset upon classification as held for sale exceeds the estimated fair value, less costs to sell.
	Accounts Receivable, net
	The following is a summary of our accounts receivable as of March 31, 2015, and December 31, 2014 (in thousands):
		March 31,				December 31,
		2015				2014
	Straight-line rental revenue receivable	$	68,462			$	73,266
	Tenant receivables	9,379				10,165
	Non-tenant receivables	984				1,150
	Allowance for doubtful accounts	(3,359		)		(1,201		)
	Total	$	75,466			$	83,380
	Deferred Financing Fees, net
	The following is a summary of our deferred financing fees as of March 31, 2015, and December 31, 2014 (in thousands):
		March 31,				December 31,
		2015				2014
	Cost	$	23,497			$	24,704
	Less: accumulated amortization	(12,807		)		(13,921		)
	Net	$	10,690			$	10,783
	Other Intangible Assets, net
	Other intangible assets consists of a ground lease on one of our properties. As of March 31, 2015, and December 31, 2014, the cost basis and accumulated amortization related to our consolidated other intangibles assets were as follows (in thousands):
		March 31,				December 31,
		2015				2014
	Cost	$	2,978			$	2,978
	Less: accumulated amortization	(864		)		(834		)
	Net	$	2,114			$	2,144
	We amortize the value of other intangible assets to expense over the estimated remaining useful life which has an ending date of December 2032.   Anticipated amortization associated with other intangible assets for each of the following five years is as follows (in thousands):
	April - December 2015	$	89
	2016	$	119
	2017	$	119
2018	$	119
2019	$	119
Real Estate Held for Sale
We classify properties as held for sale when certain criteria are met, in accordance with GAAP.  At that time, we present the assets and obligations associated with the real estate held for sale separately in our consolidated balance sheet, and we cease recording depreciation and amortization expense related to that property.  Real estate held for sale is reported at the lower of its carrying amount or its estimated fair value less estimated costs to sell.  At March 31, 2015, we had four properties classified as real estate held for sale. At December 31, 2014, we had three properties classified as real estate held for sale.
Revenue Recognition
We recognize rental income generated from all leases of consolidated real estate assets on a straight-line basis over the terms of the respective leases, including the effect of rent holidays, if any.  The total net increase to rental revenues due to straight-line rent adjustments for three months ended March 31, 2015 and 2014, was approximately $2.8 million and $1.6 million, respectively, and includes amounts recognized in discontinued operations.  Our rental revenue also includes amortization of acquired above- and below-market leases.  The total net increase to rental revenues due to the amortization of acquired above- and below-market leases for the three months ended March 31, 2015, and also for three months ended March 31, 2014, was approximately $1.2 million, and includes amounts recognized in discontinued operations. Revenues relating to lease termination fees are recognized on a straight-line basis amortized from the time that a tenant’s right to occupy the leased space is modified through the end of the revised lease term.  For the three months ended March 31, 2015 and 2014, we recognized lease termination fees of approximately $0.5 million and $0.2 million, respectively, including amounts recognized in discontinued operations.
Income Taxes
We have elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended, and have qualified as a REIT since the year ended December 31, 2004.  The Company is generally not subject to federal income taxes to the extent we distribute our REIT taxable income to our stockholders currently each year and we meet certain other organizational and operational requirements.  In addition to the Company, our business is conducted through our operating partnership, Tier OP, and various subsidiaries, including limited liability companies, partnerships, and corporations elected to be treated as taxable REIT subsidiaries.  The Company and its subsidiaries are subject to state and local income taxes on operations located in states, cities, and other jurisdictions that impose an income tax.  In addition, our taxable REIT subsidiaries are subject to federal, state, and local income taxes at regular corporate tax rates.
As of March 31, 2015, we have deferred tax liabilities of approximately $2.6 million and deferred tax assets, net of related valuation allowances, of approximately $2.4 million related to various state taxing jurisdictions.  At December 31, 2014, we had deferred tax liabilities of approximately $2.9 million and deferred tax assets, net of related valuation allowances, of approximately $2.5 million related to various state taxing jurisdictions.

New_Accounting_Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements
	In April 2014, FASB issued guidance that changes the criteria for reporting a discontinued operation. Under the new guidance, only a disposal of a component that represents a major strategic shift of an organization qualifies for discontinued operations reporting. The guidance also requires expanded disclosures about discontinued operations and new disclosures in regards to individually significant disposals that do not qualify for discontinued operations reporting. This guidance is effective for the first interim or annual period beginning on or after December 15, 2014.  Upon our adoption of this guidance on January 1, 2015, sales of our individual operating properties generally no longer qualify as discontinued operations. However, properties sold or classified as held for sale prior to January 1, 2015, continue to be reported as discontinued operations.
	In May 2014, the FASB issued guidance to clarify the principles for recognizing revenue and to develop a common revenue standard for GAAP and International Financial Reporting Standards. The standard outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. This guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2016. The FASB has proposed delaying this standard by one year. If the proposal is approved, early adoption would be permitted as of the original effective date. The guidance permits two implementation approaches, one requiring retrospective application of the new standard with restatement of prior years and one requiring prospective application of the new standard with disclosure of results under old standards. We are currently evaluating the impact this guidance will have on our financial statements when adopted.
	In June 2014, the FASB issued an update which clarifies that entities should treat performance targets that can be met after the requisite service period of a share-based payment award as performance conditions that affect vesting. The compensation expense related to such awards will be delayed until it becomes probable that the performance target will be met. This guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2015, with early adoption permitted, and may be applied either prospectively or retrospectively. We do not believe the adoption of this guidance will have a material impact on our financial statements.
	In August 2014, the FASB issued guidance regarding management’s responsibility in evaluating whether there is a substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. This guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2016. We do not believe the adoption of this guidance will have a material impact on our disclosures.
	In January 2015, the FASB issued guidance simplifying income statement presentation by eliminating the concept of extraordinary items. An entity will no longer be allowed to separately disclose extraordinary items, net of tax, in the income statement after income from continuing operations if an event or transaction is unusual in nature and occurs infrequently. This guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2015, with early adoption permitted and may be applied either prospectively or retrospectively. We do not believe the adoption of this guidance will have a material impact on our financial statements.
	In February 2015, the FASB issued updated guidance related to accounting for consolidation of certain legal entities. This guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2015, with early adoption permitted. We are currently evaluating the impact this guidance will have on our financial statements when adopted.
	In April 2015, the FASB issued guidance related to accounting for debt issuance costs. The guidance simplifies presentation by requiring debt issuance costs to be presented as a deduction from the corresponding debt liability, consistent with the presentation of debt discounts or premiums. This guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2015. We are currently evaluating the impact this guidance will have on our financial statements when adopted.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	Fair value, as defined by GAAP, is a market-based measurement, not an entity-specific measurement.  Therefore, a fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability.  As a basis for considering market participant assumptions in fair value measurements, a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the fair value hierarchy) and the reporting entity’s own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the fair value hierarchy) has been established.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	Derivative financial instruments
	We use derivative financial instruments, such as interest rate swaps, to manage our interest rate risk. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis of the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities. The fair values of interest rate swaps are determined using the market standard methodology of netting the discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts).  The variable cash payments (or receipts) are based on an expectation of future interest rates (forward curves) derived from observable market interest rate curves.
	We incorporate credit valuation adjustments (“CVAs”) to appropriately reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of our derivative contracts for the effect of nonperformance risk, we have considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees.
	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 CVAs associated with our derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by us and our counterparties.  However, we have assessed the significance of the impact of the CVAs on the overall valuation of our derivative positions and have determined that they are not significant.  As a result, we have determined that our derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy.  Unrealized gains or losses on derivatives are recorded in accumulated other comprehensive income (loss) (“OCI”) within equity at each measurement date. Our derivative financial instruments are included in “other liabilities” on our consolidated balance sheets.
	The following table sets forth our financial liabilities measured at fair value on a recurring basis, which equals book value, by level within the fair value hierarchy as of March 31, 2015, and December 31, 2014 (in thousands).
							Basis of Fair Value Measurements
							Quoted Prices In Active Markets for Identical Items (Level 1)			Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)
			Total Fair Value
	Description
	31-Mar-15
	Liabilities:
	Derivative financial instruments		$	(5,345	)		$	—		$	(5,345	)		$	—
	31-Dec-14
	Liabilities:
	Derivative financial instruments		$	(789	)		$	—		$	(789	)		$	—
	Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
	Impairment of Real Estate Related Assets
	We have recorded non-cash impairment charges related to a reduction in the fair value of certain of our assets.  The inputs used to calculate the fair value of these assets included projected cash flows and a risk-adjusted rate of return that we estimated would be used by a market participant in valuing these assets or by obtaining third party broker valuation estimates, bona fide purchase offers, or the expected sales price of an executed sales agreement.
	During the three months ended March 31, 2015, we recorded additional impairment losses of approximately $0.1 million for a property that was impaired at December 31, 2014, and was sold in 2015. During the year ended December 31, 2014, we also recorded impairment losses for a property classified as held for sale. The following table summarizes those assets which were measured at fair value and impaired during 2015 and 2014 (in thousands):
							Basis of Fair Value Measurements
	Description		Fair Value				Quoted Prices			Significant				Significant		Total
			of Assets at Impairment				In Active			Other				Unobservable		Losses
							Markets for			Observable				Inputs
							Identical Items			Inputs				(Level 3)
							(Level 1)			(Level 2)
	for the three months ended March 31, 2015
	Real estate		$	11,489			$	—		$	11,489			$	—	$	(132	)
	for the year ended December 31, 2014
	Real estate (1)		$	11,489			$	—		$	11,489			$	—	$	(4,940	)
	Real estate held for sale (2)		$	42,000			$	—		$	—			$	42,000	$	(8,225	)
	_______________
	(1) Recorded in the quarter ended December 31, 2014
	(2) Recorded in the quarter ended March 31, 2014
	Financial Instruments not Reported at Fair Value
	Financial instruments held at March 31, 2015, and December 31, 2014, but not measured at fair value on a recurring basis include cash and cash equivalents, restricted cash, accounts receivable, notes payable, accounts payable, payables to related parties, accrued liabilities and other liabilities.  With the exception of notes payable, the financial statement carrying amounts of these items approximate their fair values due to their short-term nature. Estimated fair values for notes payable have been determined using recent trading activity and/or bid-ask spreads and are classified as Level 2 in the fair value hierarchy. Carrying amounts and the related estimated fair value of our notes payable as of March 31, 2015, and December 31, 2014, are as follows (in thousands):
		31-Mar-15							31-Dec-14
		Carrying Amount				Fair			Carrying Amount				Fair
						Value							Value
	Notes payable	$	1,124,475			$	1,147,309		$	1,194,085			$	1,216,991
	Notes payable associated with real estate held for sale	$	96,824			$	95,175		$	97,257			$	95,011

Real_Estate_Activities

Real Estate Activities	3 Months Ended
	Mar. 31, 2015
Real Estate Activities [Abstract]
Real Estate Disclosure [Text Block]	Real Estate Activities
	Sales of Real Estate Reported in Continuing Operations
	The following table presents our sale of real estate for the three months ended March 31, 2015, that is reported in continuing operations (in thousands):
			Date of Disposal				Rentable Square Footage		Contract Sales Price			Proceeds from Sale
	Property Name				Location
	One and Two Chestnut Place		3/6/15		Worcester, MA		218		$	14,000		$	11,515
	The following table presents net loss related to One and Two Chestnut Place for the three months ended March 31, 2015 and 2014 (in thousands):
		Three Months Ended
		31-Mar-15				31-Mar-14
	Net loss from property sold in 2015	$	(87	)		$	(10	)
	Sales of Real Estate Reported in Discontinued Operations
	As discussed in Note 3, “New Accounting Pronouncements,” we adopted the provisions of the FASB guidance regarding the reporting of discontinued operations on January 1, 2015. The following presents our sales of real estate during the three months ended March 31, 2015, and the year ended December 31, 2014, that are reported as discontinued operations in the accompanying condensed consolidated statements of operations and comprehensive loss because they were sold or classified as held for sale on or before December 31, 2014 (in thousands):
			Date of Disposal				Rentable Square Footage			Contract Sales Price			Proceeds from Sale
	Property Name				Location
	for the three months ended March 31, 2015
	250 West Pratt (1)		3/19/15		Baltimore, MD		368			$	63,500		$	55,276
	for the year ended December 31, 2014
	City Hall Plaza		9/16/14		Manchester, NH		210			$	19,750		$	19,130
	222 South Riverside Plaza (2)		12/19/14		Chicago, IL		1,184						223,670
							1,394						$	242,800
	_____________
	(1) 250 West Pratt was held for sale at December 31, 2014, and the operations were classified as discontinued operations.
	(2) The contract sales price for the 222 South Riverside Plaza property was approximately $247.0 million in cash, excluding transaction costs, credits, prorations, and adjustments; plus the conveyance of the 5950 Sherry Lane property in Dallas, Texas.
	The table below summarizes the results of operations for each of the properties that have been classified as discontinued operations in the accompanying condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2015 and 2014 (in thousands). This includes properties sold or held for sale on or before December 31, 2014.
		Three Months Ended
		March 31, 2015				March 31, 2014
	Rental revenue	$	6,463			$	15,376
	Expenses
	Property operating expenses	2,636				5,168
	Interest expense	1,411				5,234
	Real estate taxes	941				2,798
	Asset impairment losses	—				8,225
	Property management fees	168				478
	Depreciation and amortization	—				6,461
	Total expenses	5,156				28,364
	Other expense	2				3
	Income (loss) from discontinued operations	$	1,305			$	(12,991	)
	Real Estate Held for Sale
	As of December 31, 2014, we had three properties classified as held for sale and the operations of each of those properties were classified as discontinued operations at that time. As of March 31, 2015, one of those properties has been sold, two of those properties remain classified as held for sale, and two additional properties have been classified as held for sale as summarized in the table below:
					Classification of Operations
	Property Name		Location
	Fifth Third Center (1) (2)		Cleveland, OH		Discontinued
	Fifth Third Center (1)		Columbus, OH		Discontinued
	United Plaza (3)		Philadelphia, PA		Continuing
	1650 Arch Street (3)		Philadelphia, PA		Continuing
	__________________
	(1) This property was classified as held for sale as of December 31, 2014.
	(2) On April 7, 2015, our Fifth Third Center property located in Cleveland, Ohio, was sold to an unaffiliated third party for a contract sales price of approximately $53.8 million.
	(3) On April 23, 2015, our United Plaza and 1650 Arch Street properties located in Philadelphia, Pennsylvania, were sold to an unaffiliated third party for a combined contract sales price of approximately $190.8 million.
	The major classes of assets and obligations associated with real estate held for sale as of March 31, 2015, and December 31, 2014, are as follows (in thousands):
		March 31,				31-Dec-14
		2015
	Land	$	39,791			$	10,977
	Buildings and improvements, net of approximately $65.3 million and $38.0 million in accumulated depreciation at March 31, 2015, and December 31, 2014, respectively	182,862				108,891
	Accounts receivable and other assets, net of approximately $0.1 million and $0.1 million in allowance for doubtful accounts at March 31, 2015, and December 31, 2014, respectively	12,062				7,290
	Lease intangibles, net of approximately $29.8 million and $15.5 million in accumulated amortization at March 31, 2015, and December 31, 2014, respectively	20,415				10,482
	Assets associated with real estate held for sale	$	255,130			$	137,640
	Notes payable	$	96,824			$	97,257
	Acquired below-market leases, net of approximately $3.9 million and $3.2 million in accumulated amortization at March 31, 2015, and December 31, 2014, respectively	2,187				1,513
	Other liabilities	5,446				9,573
	Obligations associated with real estate held for sale	$	104,457			$	108,343

Investments_in_Unconsolidated_

Investments in Unconsolidated Entities	3 Months Ended
	Mar. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Investments in Unconsolidated Entities	Investments in Unconsolidated Entities
	Investments in unconsolidated entities consist of our noncontrolling interests in certain properties. The following is a summary of our investments in unconsolidated entities as of March 31, 2015, and December 31, 2014 (in thousands):
		Ownership	March 31,		December 31,
		Interest	2015		2014
	Wanamaker Building	60.00%	$	38,182	$	38,609
	Paces West	10.00%	1,240		1,276
	Total		$	39,422	$	39,885
	For the three months ended March 31, 2015 and 2014, we recorded approximately $0.2 million and $0.1 million in equity in operations of investments, respectively.  Our equity in operations of investments for the three months ended March 31, 2015 and 2014, represents our proportionate share of the combined earnings and losses from these investments for the period of our ownership. For the three months ended March 31, 2015 and 2014, we recorded approximately $0.6 million and $0.4 million of distributions from our investments in unconsolidated entities, respectively.

Real_Estate_Under_Development

Real Estate Under Development	3 Months Ended
	Mar. 31, 2015
Real Estate Under Development [Abstract]
Real Estate Under Development	Real Estate Under Development
	We capitalize interest, property taxes, insurance, and direct construction costs on our real estate under development, which includes the development of a new commercial office building at Two BriarLake Plaza in Houston, Texas (“Two BriarLake Plaza”).  For the three months ended March 31, 2015, we capitalized a total of approximately $2.0 million for the development of Two BriarLake Plaza, including approximately $0.3 million in interest.  For the three months ended March 31, 2014, we capitalized a total of approximately $9.0 million for the development of Two BriarLake Plaza, including approximately $1.0 million in interest.  We completed the major construction activity of Two BriarLake Plaza in the third quarter of 2014, and the property was classified within “land” and “buildings and improvements, net” on our consolidated balance sheet at that time. Tenant improvements are ongoing and the building is not yet held as fully available for occupancy. We have a construction loan that will provide up to $66.0 million in available borrowings for the development. As of March 31, 2015, approximately $50.8 million has been drawn on the loan.

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities
	We may be exposed to the risk associated with variability of interest rates that might impact our cash flows and the results of our operations.  Our objectives in using interest rate derivatives are to add stability to interest expense and to manage our exposure to interest rate movements.  To accomplish this objective, we have used interest rate swaps as part of our interest rate risk management strategy.  Our interest rate swaps involve the receipt of variable-rate amounts from counterparties in exchange for us making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount.  Our hedging strategy of entering into interest rate swaps, therefore, is to eliminate or reduce, to the extent possible, the volatility of cash flows.
	The following table summarizes the notional values of our derivative financial instruments (in thousands) as of March 31, 2015. The notional values provide an indication of the extent of our involvement in these instruments at March 31, 2015, but do not represent exposure to credit, interest rate, or market risks.
	Type/Description		Notional Value			Index		Strike Rate		Effective Date	Maturity Date
	Interest rate swap - cash flow hedge		$	125,000		one-month LIBOR		1.6775	%	12/31/14	10/31/19
	Interest rate swap - cash flow hedge		$	125,000		one-month LIBOR		1.6935	%	4/30/15	10/31/19
	Interest rate swap - cash flow hedge		$	125,000		one-month LIBOR		1.7615	%	6/30/15	5/31/22
	Interest rate swap - cash flow hedge		$	150,000		one-month LIBOR		1.7695	%	6/30/15	5/31/22
	The table below presents the fair value of our derivative financial instruments, included in “other liabilities” on our consolidated balance sheets, as of March 31, 2015, and December 31, 2014 (in thousands):
	Derivatives designated as hedging instruments:	March 31,			December 31,
		2015			2014
	Interest rate swaps	$	(5,345	)	$	(789	)
	The tables below present the effect of the change in fair value of derivative financial instruments in our consolidated statements of operations and comprehensive loss for the three months ended March 31, 2015 and 2014 (in thousands):
	Derivatives in Cash Flow Hedging Relationship
		Gain (loss) recognized in OCI on derivative
		(effective portion)
		For the Three Months Ended
		31-Mar-15			31-Mar-14
	Interest rate swap	$	(4,556	)	$	—
		Amount reclassified from OCI into income (effective portion)
		For the Three Months Ended
	Location	31-Mar-15			31-Mar-14
	Interest expense (1)	$	471		$	—
	____________
	-1	Increases in fair value as a result of accrued interest associated with our swap transactions are recorded in accumulated OCI and subsequently reclassified into income. Such amounts are shown net in the statements of changes in equity and offset dollar for dollar.
	Amounts reported in accumulated OCI related to derivatives will be reclassified to interest expense as interest payments and accruals are made on our variable-rate debt. During the next twelve months, we estimate that approximately $6.1 million will be reclassified as an increase to interest expense.
	We have agreements with our derivative counterparties that contain provisions where if we default on any of our indebtedness for at least 30 days, during which time such default has not been remedied, and in all cases provided that the aggregate amount of all such default is not less than $10.0 million for recourse debt or $75.0 million for non-recourse debt, then we could also be declared in default on our derivative obligations.
	As of March 31, 2015, the fair value of our derivatives in a net liability position, which includes accrued interest but excludes any adjustment for nonperformance risk, related to these agreements was approximately $5.4 million. As of March 31, 2015, we have not posted any collateral related to these agreements. If we had breached any of these provisions at March 31, 2015, we could have been required to settle our obligations under the agreements at the termination value of approximately $5.4 million.

Notes_Payable

Notes Payable	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Notes Payable	Notes Payable
	Our notes payable was approximately $1.1 billion in principal amount at March 31, 2015, and excludes notes payable associated with real estate held for sale. As of March 31, 2015, all of our outstanding debt was fixed rate debt (or effectively fixed rate debt, through the use of an interest rate swap), with the exception of approximately $50.8 million from borrowings on our construction loan for Two BriarLake Plaza and approximately $96.0 million in borrowings on our revolving line of credit. As of March 31, 2015, the stated annual interest rates on our notes payable, excluding mezzanine financing, ranged from 2.28% to 6.22%. We had mezzanine financing on one property with a stated annual interest rate of 9.80%. As of March 31, 2015, the weighted average stated interest rate for our consolidated notes payable is approximately 5.03%.
	Our loan agreements generally require us to comply with certain reporting and financial covenants.  As of March 31, 2015, we believe we were in compliance with the covenants under each of our loan agreements, and our notes payable had maturity dates that range from August 2015 to August 2021.
	The following table summarizes our notes payable as of March 31, 2015 (in thousands):
	Principal payments due in:
	April - December 2015	$	121,317
	2016	560,609
	2017	130,021
	2018	97,622
	2019	126,723
	Thereafter	88,396
	Unamortized discount	(213		)
	Total (1)	$	1,124,475
	__________________
	(1) Excludes approximately $96.8 million of notes payable maturing in 2016 related to real estate held for sale.
	Credit Facility
	Through our operating partnership, Tier OP, we have a secured credit agreement providing for total borrowings of up to $475.0 million. Subject to lender approval, certain conditions, and payment of certain activation fees to the agent and lenders, this may be increased up to an additional $225.0 million in the aggregate.  The facility consists of a $250.0 million term loan and a $225.0 million revolving line of credit. The term loan matures on December 18, 2019. The revolving line of credit matures on December 18, 2018, and can be extended one additional year subject to certain conditions and payment of an extension fee. The annual interest rate on the credit facility is equal to either, at our election, (1) the “base rate” (calculated as the greatest of (i) the agent’s “prime rate”; (ii) 0.5% above the Federal Funds Effective Rate; or (iii) the LIBOR Market Index Rate plus 1.0%) plus the applicable margin or (2) LIBOR for an interest period of one, three, or six months plus the applicable margin.  The applicable margin will be determined based on the ratio of total indebtedness to total asset value and ranges from 45 basis points to 230 basis points.  All amounts owed are guaranteed by us and certain subsidiaries of Tier OP.  Draws under the credit facility are secured by a perfected first priority lien and security interest in a collateral pool consisting of ten properties owned by certain of our subsidiaries. As of March 31, 2015, we had approximately $125.0 million in borrowings outstanding under the term loan and approximately $96.0 million in borrowings outstanding under the revolving line of credit with an additional $180.3 million of borrowings available under the facility as a whole. As of March 31, 2015, the weighted average stated interest rate for borrowings under the credit facility as a whole, inclusive of our interest rate swap, was approximately 3.10%.

Equity

Equity	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Equity	Equity
	Limited Partnership Units
	At March 31, 2015, Tier OP had 432,586 units of limited partnership interest held by third parties.  These units of limited partnership interest are convertible into an equal number of shares of our common stock.
	Series A Convertible Preferred Stock
	As of March 31, 2015, we had outstanding 10,000 shares of Series A participating, voting, convertible preferred stock (the “Series A Convertible Preferred Stock”) to Behringer Harvard REIT I Services Holdings, LLC. The redemption value of these shares at March 31, 2015, is approximately $4.6 million.
	Stock Plans
	Our 2005 Incentive Award Plan allowed for equity-based incentive awards to be granted to our Employees and Key Personnel (as defined in the plan) as detailed below:
	Stock options. As of March 31, 2015, we had outstanding options held by our independent directors to purchase 75,000 shares of our common stock at a weighted average exercise price of $6.69 per share. These options have a maximum term of 10 years and were exercisable one year after the date of grant.  The options were anti-dilutive to earnings per share for each period presented.
	Restricted stock units. We have outstanding restricted stock units held by our independent directors. These units vest 13 months after the grant date. Subsequent to vesting, the restricted stock units will be converted to an equivalent number of shares of common stock upon the earlier to occur of the following events or dates: (i) separation from service for any reason other than cause; (ii) a change in control of the Company; (iii) death; or (iv) specific dates chosen by the independent directors that range from June 2015 to June 2019. Expense is measured at the grant date based on the estimated fair value of the award and is recognized over the vesting period. The restricted stock units were anti-dilutive to earnings per share for each period presented. The following is a summary of the number of restricted stock units outstanding as of March 31, 2015 and 2014:
		March 31, 2015		March 31, 2014
	Outstanding at the beginning of the year	83,043		37,407
	Outstanding at the end of the period (1)	83,043		37,407
	_____________
	(1) As of March 31, 2015, 37,407 restricted stock units are vested.
	Restricted stock. We have outstanding restricted stock held by employees. Restrictions on these shares lapse in 25% increments annually over the four-year period following the grant date.  Compensation cost is measured at the grant date, based on the estimated fair value of the award and is recognized as expense over the service period based on a tiered lapse schedule and estimated forfeiture rates.  The restricted stock was anti-dilutive to earnings per share for each period presented.   The following is a summary of the number of shares of restricted stock outstanding as of March 31, 2015 and 2014:
		31-Mar-15		31-Mar-14
	Outstanding at the beginning of the year	711,376		423,325
	Issued (1)	640,865		450,065
	Restrictions lapsed (2)	(202,354	)	(105,831	)
	Outstanding at the end of the period	1,149,887		767,559
	_____________
	(1) Shares issued in 2015 had a grant price of $4.48 per share. Shares issued in 2014 had a grant price of $4.20 per share.
	(2) 60,376 and 33,592 of these shares were surrendered in 2015 and 2014, respectively, to pay withholding tax.

Related_Party_Arrangements

Related Party Arrangements	3 Months Ended
	Mar. 31, 2015
Related Party Transactions [Abstract]
Related Party Arrangements	Related Party Arrangements
	We purchase certain administrative services from BHT Advisors, LLC (“BHT Advisors”), such as human resources, shareholder services, and information technology. We also pay BHT Advisors acquisition fees related to the development of Two BriarLake Plaza. HPT Management Services, LLC (“HPT Management”) provides property management services for our properties. Current board members, Messrs. Robert S. Aisner and M. Jason Mattox, serve as officers and are partial owners of the ultimate parent entity of BHT Advisors and HPT Management.
	Pursuant to the administrative services agreement entered into on August 31, 2012, we provided notice to BHT Advisors on April 1, 2015, of our termination of the administrative services agreement effective June 30, 2015. Upon notice of termination, we were required to pay BHT Advisors approximately $2.7 million, which represents 0.75 times the gross amount of all service charges payable with respect to such terminated services for the trailing 12-month period ending with the last full month prior to the delivery of notice of termination.
	Pursuant to the property management agreement entered into on August 31, 2012, we provided notice to HPT Management on April 1, 2015, of the exercise of our buyout option and proposed a closing to occur on June 30, 2015, whereupon (1) we will acquire and assume certain assets and certain liabilities of HPT Management and (2) HPT Management will be deemed to have irrevocably waived the non-solicitation and non-hire provisions of the management agreement with respect to certain persons, including employees of HPT Management providing property management functions on our behalf. Upon closing of the buyout, we will be required to pay HPT Management an amount, in cash, equal to 0.8 times the gross amount of all management and oversight fees earned by HPT Management under the management agreement for the trailing 12-month period ending with the last full month prior to delivery of the notice.
	The following is a summary of the related party fees and costs we incurred with BHT Advisors and HPT Management during the three months ended March 31, 2015 and 2014 (in thousands):
		Three Months Ended
		31-Mar-15		31-Mar-14
	BHT Advisors, acquisition fees	$	100	$	207
	BHT Advisors, cost of services provided	650		640
	HPT Management, property and construction management fees	2,870		2,794
	HPT Management, reimbursement of costs and expenses	4,256		4,497
	Total	$	7,876	$	8,138
	Expensed	$	7,316	$	7,643
	Capitalized to real estate under development	—		207
	Capitalized to buildings and improvements, net	560		288
	Total	$	7,876	$	8,138
	At March 31, 2015, and December 31, 2014, we had payables to related parties of approximately $2.3 million and $2.0 million, respectively, consisting primarily of expense reimbursements payable to BHT Advisors and property management fees payable to HPT Management.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	As of March 31, 2015, we had commitments of approximately $39.5 million for future tenant improvements, leasing commissions, and completing renovations at a property that was sold.
	We have Employment Agreements (collectively, the “Employment Agreements”) with five of our executive officers.  The term of each Employment Agreement ends on May 31, 2017, provided that the term will automatically continue for an additional one-year period unless either party provides 60 days written notice of non-renewal prior to the expiration of the initial term.  The agreements provide for lump sum payments and an immediate lapse of restrictions on compensation received under the long-term incentive plan upon termination of employment without cause.  As a result, in the event the Company had terminated all of these agreements without cause as of March 31, 2015, we would have recognized approximately $12.5 million in additional compensation expense.

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	3 Months Ended
	Mar. 31, 2015
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information
	Supplemental cash flow information is summarized below for the three months ended March 31, 2015 and 2014 (in thousands):
		Three Months Ended
		March 31, 2015		March 31, 2014
	Interest paid, net of amounts capitalized	$	14,842	$	18,387
	Income taxes paid	$	125	$	61
	Non-cash investing activities:
	Property and equipment additions in accounts payable and accrued liabilities	$	16,571	$	17,168
	Amortization of deferred financing fees in building and improvements, net	$	84	$	—
	Non-cash financing activities:
	Financing costs in accrued liabilities and payables to related parties	$	190	$	—
	Unrealized loss on interest rate derivatives in other liabilities	$	4,556	$	—

Basis_of_Presentation_and_Sign1

Basis of Presentation and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Real Estate	Real Estate
	As of March 31, 2015, and December 31, 2014, the cost basis and accumulated depreciation and amortization related to our consolidated real estate properties and related lease intangibles were as follows (in thousands):
							Lease Intangibles
							Assets						Liabilities
										Acquired Above-Market Leases			Acquired Below-Market Leases
			Buildings and Improvements				Other Lease Intangibles
	as of March 31, 2015
	Cost		$	1,895,389			$	181,267		$	4,074		$	(56,404	)
	Less: accumulated depreciation and amortization		(534,466		)		(103,787		)	(3,911		)	42,023
	Net		$	1,360,923			$	77,480		$	163		$	(14,381	)
							Lease Intangibles
							Assets						Liabilities
										Acquired Above-Market Leases			Acquired Below-Market Leases
			Buildings and Improvements				Other Lease Intangibles
	as of December 31, 2014
	Cost		$	2,039,765			$	215,913		$	11,785		$	(59,605	)
	Less: accumulated depreciation and amortization		(557,429		)		(123,242		)	(9,766		)	42,621
	Net		$	1,482,336			$	92,671		$	2,019		$	(16,984	)
	We amortize the value of in-place leases, in-place tenant improvements, and in-place leasing commissions to expense over the initial term of the respective leases.  The tenant relationship values are amortized to expense over the tenants’ respective initial lease terms and any anticipated renewal periods, but in no event does the amortization period for intangible assets or liabilities exceed the remaining depreciable life of the building.  Should a tenant terminate its lease, the unamortized portion of the acquired lease intangibles related to that tenant would be charged to expense.  The estimated remaining average useful lives for acquired lease intangibles range from an ending date of April 2015 to an ending date of December 2030.  Anticipated amortization associated with the acquired lease intangibles for each of the following five years is as follows (in thousands):
	April - December 2015	$	2,375
	2016	$	1,185
	2017	$	579
	2018	$	(145	)
	2019	$	475
Impairment of Real Estate Related Assets	Impairment of Real Estate Related Assets
	For our consolidated real estate assets, we monitor events and changes in circumstances indicating that the carrying amounts of the real estate assets may not be recoverable.  When such events or changes in circumstances are present, we assess potential impairment by comparing estimated future undiscounted cash flows expected to be generated over the life of the asset including its eventual disposition, to the carrying amount of the asset.  In the event that the carrying amount exceeds the estimated future undiscounted cash flows and also exceeds the fair value of the asset, we recognize an impairment loss to adjust the carrying amount of the asset to its estimated fair value. Our process to estimate the fair value of an asset involves using third party broker valuation estimates, bona fide purchase offers or the expected sales price of an executed sales agreement, which would be considered Level 1 or Level 2 assumptions within the fair value hierarchy. To the extent that this type of third party information is unavailable, we estimate projected cash flows and a risk-adjusted rate of return that we believe would be used by a third party market participant in estimating the fair value of an asset. This is considered a Level 3 assumption within the fair value hierarchy. These projected cash flows are prepared internally by the Company’s asset management professionals and are updated quarterly to reflect in place and projected leasing activity, market revenue and expense growth rates, market capitalization rates, discount rates, and changes in economic and other relevant conditions. The Company’s Chief Financial Officer, Chief Investment Officer, and Chief Accounting Officer review these projected cash flows to assure that the valuation is prepared using reasonable inputs and assumptions which are consistent with market data or with assumptions that would be used by a third party market participant and assume the highest and best use of the real estate investment. For the three months ended March 31, 2015 and 2014, we recorded non-cash impairment charges including amounts recognized in discontinued operations totaling approximately $0.1 million and $8.2 million, respectively, related to the impairment of consolidated real estate assets.  The impairment loss recorded in 2015 within continuing operations related to final estimated closing costs incurred in connection with the disposition of One and Two Chestnut Place. The impairment loss recorded in 2014 related to an asset assessed for impairment due to a change in management’s estimate of the intended hold period.
	For our unconsolidated real estate assets, at each reporting date we compare the estimated fair value of our investment to the carrying amount.  An impairment charge is recorded to the extent the fair value of our investment is less than the carrying amount and the decline in value is determined to be other than a temporary decline.  We had no impairment charges related to our investments in unconsolidated entities for the three months ended March 31, 2015 or 2014.
	In evaluating our investments for impairment, management makes several estimates and assumptions, including, but not limited to, the projected date of disposition (the intended hold period) and sales price for each property, the estimated future cash flows of each property during our estimated ownership period, and for unconsolidated investments, the estimated future distributions from the investment.  A change in these estimates and assumptions could result in understating or overstating the carrying amount of our investments which could be material to our financial statements.
	We undergo continuous evaluations of property level performance, credit market conditions, and financing options.  If our assumptions regarding the cash flows expected to result from the use and eventual disposition of our properties decrease or our expected hold periods decrease, we may incur future impairment charges on our real estate related assets.  In addition, we may incur impairment charges on assets classified as held for sale in the future if the carrying amount of the asset upon classification as held for sale exceeds the estimated fair value, less costs to sell.
Accounts Receivable, net	Accounts Receivable, net
	The following is a summary of our accounts receivable as of March 31, 2015, and December 31, 2014 (in thousands):
		March 31,				December 31,
		2015				2014
	Straight-line rental revenue receivable	$	68,462			$	73,266
	Tenant receivables	9,379				10,165
	Non-tenant receivables	984				1,150
	Allowance for doubtful accounts	(3,359		)		(1,201		)
	Total	$	75,466			$	83,380
Deferred Financing Fees, net	Deferred Financing Fees, net
	The following is a summary of our deferred financing fees as of March 31, 2015, and December 31, 2014 (in thousands):
		March 31,				December 31,
		2015				2014
	Cost	$	23,497			$	24,704
	Less: accumulated amortization	(12,807		)		(13,921		)
	Net	$	10,690			$	10,783
Other Intangible Assets, net	Other Intangible Assets, net
	Other intangible assets consists of a ground lease on one of our properties. As of March 31, 2015, and December 31, 2014, the cost basis and accumulated amortization related to our consolidated other intangibles assets were as follows (in thousands):
		March 31,				December 31,
		2015				2014
	Cost	$	2,978			$	2,978
	Less: accumulated amortization	(864		)		(834		)
	Net	$	2,114			$	2,144
	We amortize the value of other intangible assets to expense over the estimated remaining useful life which has an ending date of December 2032.   Anticipated amortization associated with other intangible assets for each of the following five years is as follows (in thousands):
	April - December 2015	$	89
	2016	$	119
	2017	$	119
	2018	$	119
	2019	$	119
Real Estate Held for Sale	Real Estate Held for Sale
	We classify properties as held for sale when certain criteria are met, in accordance with GAAP.  At that time, we present the assets and obligations associated with the real estate held for sale separately in our consolidated balance sheet, and we cease recording depreciation and amortization expense related to that property.  Real estate held for sale is reported at the lower of its carrying amount or its estimated fair value less estimated costs to sell.  At March 31, 2015, we had four properties classified as real estate held for sale. At December 31, 2014, we had three properties classified as real estate held for sale.
Revenue Recognition	Revenue Recognition
	We recognize rental income generated from all leases of consolidated real estate assets on a straight-line basis over the terms of the respective leases, including the effect of rent holidays, if any.  The total net increase to rental revenues due to straight-line rent adjustments for three months ended March 31, 2015 and 2014, was approximately $2.8 million and $1.6 million, respectively, and includes amounts recognized in discontinued operations.  Our rental revenue also includes amortization of acquired above- and below-market leases.  The total net increase to rental revenues due to the amortization of acquired above- and below-market leases for the three months ended March 31, 2015, and also for three months ended March 31, 2014, was approximately $1.2 million, and includes amounts recognized in discontinued operations. Revenues relating to lease termination fees are recognized on a straight-line basis amortized from the time that a tenant’s right to occupy the leased space is modified through the end of the revised lease term.  For the three months ended March 31, 2015 and 2014, we recognized lease termination fees of approximately $0.5 million and $0.2 million, respectively, including amounts recognized in discontinued operations.
Income Taxes	Income Taxes
	We have elected to be taxed as a REIT under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended, and have qualified as a REIT since the year ended December 31, 2004.  The Company is generally not subject to federal income taxes to the extent we distribute our REIT taxable income to our stockholders currently each year and we meet certain other organizational and operational requirements.  In addition to the Company, our business is conducted through our operating partnership, Tier OP, and various subsidiaries, including limited liability companies, partnerships, and corporations elected to be treated as taxable REIT subsidiaries.  The Company and its subsidiaries are subject to state and local income taxes on operations located in states, cities, and other jurisdictions that impose an income tax.  In addition, our taxable REIT subsidiaries are subject to federal, state, and local income taxes at regular corporate tax rates.
	As of March 31, 2015, we have deferred tax liabilities of approximately $2.6 million and deferred tax assets, net of related valuation allowances, of approximately $2.4 million related to various state taxing jurisdictions.  At December 31, 2014, we had deferred tax liabilities of approximately $2.9 million and deferred tax assets, net of related valuation allowances, of approximately $2.5 million related to various state taxing jurisdictions.

Basis_of_Presentation_and_Sign2

Basis of Presentation and Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2015
Real Estate [Abstract]
Schedule of cost basis, accumulated depreciation and amortization related to entity's consolidated real estate properties and related lease intangibles	As of March 31, 2015, and December 31, 2014, the cost basis and accumulated depreciation and amortization related to our consolidated real estate properties and related lease intangibles were as follows (in thousands):
							Lease Intangibles
							Assets						Liabilities
										Acquired Above-Market Leases			Acquired Below-Market Leases
			Buildings and Improvements				Other Lease Intangibles
	as of March 31, 2015
	Cost		$	1,895,389			$	181,267		$	4,074		$	(56,404	)
	Less: accumulated depreciation and amortization		(534,466		)		(103,787		)	(3,911		)	42,023
	Net		$	1,360,923			$	77,480		$	163		$	(14,381	)
							Lease Intangibles
							Assets						Liabilities
										Acquired Above-Market Leases			Acquired Below-Market Leases
			Buildings and Improvements				Other Lease Intangibles
	as of December 31, 2014
	Cost		$	2,039,765			$	215,913		$	11,785		$	(59,605	)
	Less: accumulated depreciation and amortization		(557,429		)		(123,242		)	(9,766		)	42,621
	Net		$	1,482,336			$	92,671		$	2,019		$	(16,984	)
Anticipated amortization associated with the acquired lease intangibles for each of the five years	Anticipated amortization associated with the acquired lease intangibles for each of the following five years is as follows (in thousands):
	April - December 2015	$	2,375
	2016	$	1,185
	2017	$	579
	2018	$	(145	)
	2019	$	475
Accounts Receivable [Abstract]
Summary of net accounts receivable	The following is a summary of our accounts receivable as of March 31, 2015, and December 31, 2014 (in thousands):
		March 31,				December 31,
		2015				2014
	Straight-line rental revenue receivable	$	68,462			$	73,266
	Tenant receivables	9,379				10,165
	Non-tenant receivables	984				1,150
	Allowance for doubtful accounts	(3,359		)		(1,201		)
	Total	$	75,466			$	83,380
Deferred Financing Fees, net [Abstract]
Schedule of deferred financing fees	The following is a summary of our deferred financing fees as of March 31, 2015, and December 31, 2014 (in thousands):
		March 31,				December 31,
		2015				2014
	Cost	$	23,497			$	24,704
	Less: accumulated amortization	(12,807		)		(13,921		)
	Net	$	10,690			$	10,783
Other Intangible Assets, Net [Abstract]
Schedule of other intangible assets	As of March 31, 2015, and December 31, 2014, the cost basis and accumulated amortization related to our consolidated other intangibles assets were as follows (in thousands):
		March 31,				December 31,
		2015				2014
	Cost	$	2,978			$	2,978
	Less: accumulated amortization	(864		)		(834		)
	Net	$	2,114			$	2,144
Anticipated amortization associated with other intangible assets for each of the five years	Anticipated amortization associated with other intangible assets for each of the following five years is as follows (in thousands):
	April - December 2015	$	89
	2016	$	119
	2017	$	119
	2018	$	119
	2019	$	119

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]	The following table sets forth our financial liabilities measured at fair value on a recurring basis, which equals book value, by level within the fair value hierarchy as of March 31, 2015, and December 31, 2014 (in thousands).
							Basis of Fair Value Measurements
							Quoted Prices In Active Markets for Identical Items (Level 1)			Significant Other Observable Inputs (Level 2)				Significant Unobservable Inputs (Level 3)
			Total Fair Value
	Description
	31-Mar-15
	Liabilities:
	Derivative financial instruments		$	(5,345	)		$	—		$	(5,345	)		$	—
	31-Dec-14
	Liabilities:
	Derivative financial instruments		$	(789	)		$	—		$	(789	)		$	—
Fair Value Measurements, Nonrecurring	The following table summarizes those assets which were measured at fair value and impaired during 2015 and 2014 (in thousands):
							Basis of Fair Value Measurements
	Description		Fair Value				Quoted Prices			Significant				Significant		Total
			of Assets at Impairment				In Active			Other				Unobservable		Losses
							Markets for			Observable				Inputs
							Identical Items			Inputs				(Level 3)
							(Level 1)			(Level 2)
	for the three months ended March 31, 2015
	Real estate		$	11,489			$	—		$	11,489			$	—	$	(132	)
	for the year ended December 31, 2014
	Real estate (1)		$	11,489			$	—		$	11,489			$	—	$	(4,940	)
	Real estate held for sale (2)		$	42,000			$	—		$	—			$	42,000	$	(8,225	)
Schedule of carrying amounts and related estimated fair value of notes payable	Carrying amounts and the related estimated fair value of our notes payable as of March 31, 2015, and December 31, 2014, are as follows (in thousands):
		31-Mar-15							31-Dec-14
		Carrying Amount				Fair			Carrying Amount				Fair
						Value							Value
	Notes payable	$	1,124,475			$	1,147,309		$	1,194,085			$	1,216,991
	Notes payable associated with real estate held for sale	$	96,824			$	95,175		$	97,257			$	95,011

Real_Estate_Activities_Tables

Real Estate Activities (Tables)	3 Months Ended
	Mar. 31, 2015
Real Estate Activities [Abstract]
Schedule of Real Estate Dispositions, Continuing Operations Table [Table Text Block]	The following table presents our sale of real estate for the three months ended March 31, 2015, that is reported in continuing operations (in thousands):
			Date of Disposal				Rentable Square Footage		Contract Sales Price			Proceeds from Sale
	Property Name				Location
	One and Two Chestnut Place		3/6/15		Worcester, MA		218		$	14,000		$	11,515
Net Income effect from sales of real estate [Table Text Block]	The following table presents net loss related to One and Two Chestnut Place for the three months ended March 31, 2015 and 2014 (in thousands):
		Three Months Ended
		31-Mar-15				31-Mar-14
	Net loss from property sold in 2015	$	(87	)		$	(10	)
Schedule of Real Estate Dispositions, Discontinued Operations [Table Text Block]	The following presents our sales of real estate during the three months ended March 31, 2015, and the year ended December 31, 2014, that are reported as discontinued operations in the accompanying condensed consolidated statements of operations and comprehensive loss because they were sold or classified as held for sale on or before December 31, 2014 (in thousands):
			Date of Disposal				Rentable Square Footage			Contract Sales Price			Proceeds from Sale
	Property Name				Location
	for the three months ended March 31, 2015
	250 West Pratt (1)		3/19/15		Baltimore, MD		368			$	63,500		$	55,276
	for the year ended December 31, 2014
	City Hall Plaza		9/16/14		Manchester, NH		210			$	19,750		$	19,130
	222 South Riverside Plaza (2)		12/19/14		Chicago, IL		1,184						223,670
							1,394						$	242,800
	_____________
	(1) 250 West Pratt was held for sale at December 31, 2014, and the operations were classified as discontinued operations.
	(2) The contract sales price for the 222 South Riverside Plaza property was approximately $247.0 million in cash, excluding transaction costs, credits, prorations, and adjustments; plus the conveyance of the 5950 Sherry Lane property in Dallas, Texas.
Schedule of Disposal Groups Including Discontinued Operations Income Statement [Table Text Block]	The table below summarizes the results of operations for each of the properties that have been classified as discontinued operations in the accompanying condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2015 and 2014 (in thousands). This includes properties sold or held for sale on or before December 31, 2014.
		Three Months Ended
		March 31, 2015				March 31, 2014
	Rental revenue	$	6,463			$	15,376
	Expenses
	Property operating expenses	2,636				5,168
	Interest expense	1,411				5,234
	Real estate taxes	941				2,798
	Asset impairment losses	—				8,225
	Property management fees	168				478
	Depreciation and amortization	—				6,461
	Total expenses	5,156				28,364
	Other expense	2				3
	Income (loss) from discontinued operations	$	1,305			$	(12,991	)
Schedule of Assets and Liabilities Associated with Real Estate Held for Sale [Table Text Block]	The major classes of assets and obligations associated with real estate held for sale as of March 31, 2015, and December 31, 2014, are as follows (in thousands):
		March 31,				31-Dec-14
		2015
	Land	$	39,791			$	10,977
	Buildings and improvements, net of approximately $65.3 million and $38.0 million in accumulated depreciation at March 31, 2015, and December 31, 2014, respectively	182,862				108,891
	Accounts receivable and other assets, net of approximately $0.1 million and $0.1 million in allowance for doubtful accounts at March 31, 2015, and December 31, 2014, respectively	12,062				7,290
	Lease intangibles, net of approximately $29.8 million and $15.5 million in accumulated amortization at March 31, 2015, and December 31, 2014, respectively	20,415				10,482
	Assets associated with real estate held for sale	$	255,130			$	137,640
	Notes payable	$	96,824			$	97,257
	Acquired below-market leases, net of approximately $3.9 million and $3.2 million in accumulated amortization at March 31, 2015, and December 31, 2014, respectively	2,187				1,513
	Other liabilities	5,446				9,573
	Obligations associated with real estate held for sale	$	104,457			$	108,343

Investments_in_Unconsolidated_1

Investments in Unconsolidated Entities (Tables)	3 Months Ended
	Mar. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Summary of the entity's investments in unconsolidated entities	The following is a summary of our investments in unconsolidated entities as of March 31, 2015, and December 31, 2014 (in thousands):
		Ownership	March 31,		December 31,
		Interest	2015		2014
	Wanamaker Building	60.00%	$	38,182	$	38,609
	Paces West	10.00%	1,240		1,276
	Total		$	39,422	$	39,885

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments [Table Text Block]	The following table summarizes the notional values of our derivative financial instruments (in thousands) as of March 31, 2015. The notional values provide an indication of the extent of our involvement in these instruments at March 31, 2015, but do not represent exposure to credit, interest rate, or market risks.
	Type/Description		Notional Value			Index		Strike Rate		Effective Date	Maturity Date
	Interest rate swap - cash flow hedge		$	125,000		one-month LIBOR		1.6775	%	12/31/14	10/31/19
	Interest rate swap - cash flow hedge		$	125,000		one-month LIBOR		1.6935	%	4/30/15	10/31/19
	Interest rate swap - cash flow hedge		$	125,000		one-month LIBOR		1.7615	%	6/30/15	5/31/22
	Interest rate swap - cash flow hedge		$	150,000		one-month LIBOR		1.7695	%	6/30/15	5/31/22
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The table below presents the fair value of our derivative financial instruments, included in “other liabilities” on our consolidated balance sheets, as of March 31, 2015, and December 31, 2014 (in thousands):
	Derivatives designated as hedging instruments:	March 31,			December 31,
		2015			2014
	Interest rate swaps	$	(5,345	)	$	(789	)
Derivative Instruments, Gain (Loss) [Table Text Block]	The tables below present the effect of the change in fair value of derivative financial instruments in our consolidated statements of operations and comprehensive loss for the three months ended March 31, 2015 and 2014 (in thousands):
	Derivatives in Cash Flow Hedging Relationship
		Gain (loss) recognized in OCI on derivative
		(effective portion)
		For the Three Months Ended
		31-Mar-15			31-Mar-14
	Interest rate swap	$	(4,556	)	$	—
		Amount reclassified from OCI into income (effective portion)
		For the Three Months Ended
	Location	31-Mar-15			31-Mar-14
	Interest expense (1)	$	471		$	—
	____________
	-1	Increases in fair value as a result of accrued interest associated with our swap transactions are recorded in accumulated OCI and subsequently reclassified into income. Such amounts are shown net in the statements of changes in equity and offset dollar for dollar.

Notes_Payable_Tables

Notes Payable (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Summary of notes payable scheduled principal payments	The following table summarizes our notes payable as of March 31, 2015 (in thousands):
	Principal payments due in:
	April - December 2015	$	121,317
	2016	560,609
	2017	130,021
	2018	97,622
	2019	126,723
	Thereafter	88,396
	Unamortized discount	(213		)
	Total (1)	$	1,124,475
	__________________
	(1) Excludes approximately $96.8 million of notes payable maturing in 2016 related to real estate held for sale.

Equity_Tables

Equity (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Schedule of Restricted Stock Units	The following is a summary of the number of restricted stock units outstanding as of March 31, 2015 and 2014:
		March 31, 2015		March 31, 2014
	Outstanding at the beginning of the year	83,043		37,407
	Outstanding at the end of the period (1)	83,043		37,407
	_____________
	(1) As of March 31, 2015, 37,407 restricted stock units are vested.
Schedule of Share-based Compensation Arrangement, Restricted Stock	The following is a summary of the number of shares of restricted stock outstanding as of March 31, 2015 and 2014:
		31-Mar-15		31-Mar-14
	Outstanding at the beginning of the year	711,376		423,325
	Issued (1)	640,865		450,065
	Restrictions lapsed (2)	(202,354	)	(105,831	)
	Outstanding at the end of the period	1,149,887		767,559
	_____________
	(1) Shares issued in 2015 had a grant price of $4.48 per share. Shares issued in 2014 had a grant price of $4.20 per share.
	(2) 60,376 and 33,592 of these shares were surrendered in 2015 and 2014, respectively, to pay withholding tax

Related_Party_Arrangements_Tab

Related Party Arrangements (Tables)	3 Months Ended
	Mar. 31, 2015
Related Party Transactions [Abstract]
Schedule of related party transactions	The following is a summary of the related party fees and costs we incurred with BHT Advisors and HPT Management during the three months ended March 31, 2015 and 2014 (in thousands):
		Three Months Ended
		31-Mar-15		31-Mar-14
	BHT Advisors, acquisition fees	$	100	$	207
	BHT Advisors, cost of services provided	650		640
	HPT Management, property and construction management fees	2,870		2,794
	HPT Management, reimbursement of costs and expenses	4,256		4,497
	Total	$	7,876	$	8,138
	Expensed	$	7,316	$	7,643
	Capitalized to real estate under development	—		207
	Capitalized to buildings and improvements, net	560		288
	Total	$	7,876	$	8,138

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	3 Months Ended
	Mar. 31, 2015
Supplemental Cash Flow Elements [Abstract]
Schedule of supplemental cash flow information	Supplemental cash flow information is summarized below for the three months ended March 31, 2015 and 2014 (in thousands):
		Three Months Ended
		March 31, 2015		March 31, 2014
	Interest paid, net of amounts capitalized	$	14,842	$	18,387
	Income taxes paid	$	125	$	61
	Non-cash investing activities:
	Property and equipment additions in accounts payable and accrued liabilities	$	16,571	$	17,168
	Amortization of deferred financing fees in building and improvements, net	$	84	$	—
	Non-cash financing activities:
	Financing costs in accrued liabilities and payables to related parties	$	190	$	—
	Unrealized loss on interest rate derivatives in other liabilities	$	4,556	$	—

Business_Details

Business (Details)	Mar. 31, 2015	Dec. 31, 2014
	state	property
	property
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of properties in which ownership interest is held by the entity	34
Number of Properties Held for Sale	4	3
Number of recently developed non-operating properties	1
Number of retail properties	1
Number of markets in which the entity owned interests in properties	17

Basis_of_Presentation_and_Sign3

Basis of Presentation and Significant Accounting Policies (Real Estate) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Real estate properties
Buildings and improvements, net	$1,360,923	$1,482,336
Finite-Lived Intangible Assets, Net [Abstract]
Lease intangibles, net	77,643	94,690
Intangible liabilities
Net	-14,381	-16,984
Other Lease Intangibles
Finite-Lived Intangible Assets, Net [Abstract]
Cost	181,267	215,913
Less: accumulated depreciation and amortization	-103,787	-123,242
Lease intangibles, net	77,480	92,671
Acquired Above-Market Leases
Finite-Lived Intangible Assets, Net [Abstract]
Cost	4,074	11,785
Less: accumulated depreciation and amortization	-3,911	-9,766
Lease intangibles, net	163	2,019
Leases, Acquired-in-Place, Market Adjustment [Member]
Intangible liabilities
Cost	-56,404	-59,605
Less: accumulated depreciation and amortization	42,023	42,621
Net	-14,381	-16,984
Leases, Acquired-in-Place Amortization
Anticipated amortization associated with the acquired lease intangibles for each of the following five years
April - December 2015	2,375
2016	1,185
2017	579
2018	-145
2019	475
Building and Building Improvements [Member]
Real estate properties
Cost	1,895,389	2,039,765
Less: accumulated depreciation and amortization	-534,466	-557,429
Buildings and improvements, net	$1,360,923	$1,482,336

Basis_of_Presentation_and_Sign4

Basis of Presentation and Significant Accounting Policies (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
	property	property
Schedule of Real Estate Properties and Related Lease Intangibles [Line Items]
Number of Properties Held for Sale	4	3
Number of Properties Subject to Ground Leases	1
Asset Impairment Charges Including Discontinued Operations	$132	$4,940	$8,225
Accounts Receivable [Abstract]
Straight-line rental revenue receivable	68,462	73,266
Tenant receivables	9,379	10,165
Non-tenant receivables	984	1,150
Allowance for doubtful accounts	-3,359	-1,201
Total	75,466	83,380
Deferred Financing Fees, net [Abstract]
Cost	23,497	24,704
Less: Accumulated amortization	-12,807	-13,921
Net	10,690	10,783
Other Intangible Assets, Net [Abstract]
Cost	2,978	2,978
less: accumulated amortization	-864	-834
Net	2,114	2,144
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
April - December 2015	89
2016	119
2017	119
2018	119
2019	$119

Basis_of_Presentation_and_Sign5

Basis of Presentation and Significant Accounting Policies (Revenue Recognition and Income Taxes) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Revenue Recognition [Abstract]
Net increase in rental revenues due to straight-line rent adjustments	$2,800,000	$1,600,000
Net increase in rental revenue due to amortization of above and below market leases	1,187,000	1,154,000
Lease termination fee revenue	500,000	200,000
Income Taxes
Deferred tax liabilities	2,600,000		2,900,000
Deferred tax assets, net of related valuation allowances	$2,400,000		$2,500,000

Fair_Value_Measurements_Financ

Fair Value Measurements (Financial Instruments not reported at Fair Value) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Notes Payable
Carrying Amount	$1,124,475	$1,194,085
Fair Value, Measurements, Recurring [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	0	0
Fair Value, Measurements, Recurring [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	-5,345	-789
Fair Value, Measurements, Recurring [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	0	0
Total Fair Value | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability	($5,345)	($789)

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Assets measured at fair value
Real Estate Investment Property, Net	$1,609,953	$1,768,766
Asset Impairment Charges Including Discontinued Operations	-132	-4,940	-8,225
Assets associated with real estate held for sale	255,130	137,640
Asset impairment losses	0		-8,225
Fair Value, Measurements, Nonrecurring [Member] | Level 1
Assets measured at fair value
Real Estate Investment Property, Net	0	0
Assets associated with real estate held for sale		0
Fair Value, Measurements, Nonrecurring [Member] | Level 2
Assets measured at fair value
Real Estate Investment Property, Net	11,489	11,489
Assets associated with real estate held for sale		0
Fair Value, Measurements, Nonrecurring [Member] | Level 3
Assets measured at fair value
Real Estate Investment Property, Net	0	0
Fair Value, Measurements, Nonrecurring [Member] | Real Estate [Member] | Level 3
Assets measured at fair value
Assets, Fair Value Disclosure		42,000
Carrying Amount | Level 2
Assets measured at fair value
Notes Payable, Fair Value Disclosure	1,124,475	1,194,085
Notes Payable held for sale, Fair Value Disclosure	96,824	97,257
Total Fair Value | Level 2
Assets measured at fair value
Notes Payable, Fair Value Disclosure	1,147,309	1,216,991
Notes Payable held for sale, Fair Value Disclosure	95,175	95,011
Total Fair Value | Fair Value, Measurements, Nonrecurring [Member]
Assets measured at fair value
Real Estate Investment Property, Net	11,489	11,489
Assets associated with real estate held for sale		$42,000

Real_Estate_Activities_Details

Real Estate Activities (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Mar. 06, 2015	Mar. 19, 2015	Sep. 16, 2014	Dec. 19, 2014
				sqft	sqft	sqft	sqft
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net loss	($5,902,000)	($29,657,000)
Proceeds from sale of discontinued operations	55,276,000	0
One & Two Chestnut Place Worcester Ma [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area				218,000
Contract Sale Price				14,000,000
Net loss	-87,000	-10,000
Proceeds from sale of discontinued operations	11,515,000
250 W Pratt Baltimore Md [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area					368,000
Contract Sale Price					63,500,000
Proceeds from sale of discontinued operations	55,276,000
City Hall Plaza Manchester Nh [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area						210,000
Contract Sale Price						19,750,000
Proceeds from sale of discontinued operations			19,130,000
222 South Riverside Plaza Chicago Illinois [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contract price, cash portion							247,000,000
Net Rentable Area							1,184,000
Proceeds from sale of discontinued operations			223,670,000
Disposed Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Rentable Area			1,394,000
Proceeds from sale of discontinued operations			$242,800,000

Real_Estate_Activities_Details1

Real Estate Activities (Details) 2 (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Apr. 23, 2015	Apr. 07, 2015
	property		property
Discontinued Operations
Rental revenue	$6,463	$15,376
Property operating expense	2,636	5,168
Interest expense	1,411	5,234
Real estate taxes	941	2,798
Asset impairment losses	0	8,225
Property management fees	168	478
Depreciation and amortization	0	6,461
Total expenses	5,156	28,364
Other expense	2	3
Income (loss) from discontinued operations	1,305	-12,991
Long lived assets held for sale [Abstract]
Land	249,030		286,430
Building and improvements, net	1,360,923		1,482,336
Allowance for Doubtful Accounts Receivable	3,359		1,201
Lease intangibles, net	77,643		94,690
Assets associated with real estate held for sale	255,130		137,640
Notes payable	1,124,475		1,194,085
Acquired below-market leases, net	14,381		16,984
Obligations associated with real estate held for sale	104,457		108,343
Number of Properties Held for Sale	4		3
Number of Properties Sold (previously held for sale)	1
Number of properties that remain held for sale	2
Number of additional properties classified as held for sale	2
Building and Building Improvements [Member]
Long lived assets held for sale [Abstract]
Building and improvements, net	1,360,923		1,482,336
Accumulated depreciation and amortization	534,466		557,429
Assets Held-for-sale [Member]
Long lived assets held for sale [Abstract]
Land	39,791		10,977
Building and improvements, net	182,862		108,891
Accounts Receivable and Other Assets, net Held for Sale	12,062		7,290
Allowance for Doubtful Accounts Receivable	100		100
Lease intangibles, net	20,415		10,482
Notes payable	96,824		97,257
Acquired below-market leases, net	2,187		1,513
Other liabilities	5,446		9,573
Assets Held-for-sale [Member] | Building and Building Improvements [Member]
Long lived assets held for sale [Abstract]
Accumulated depreciation and amortization	65,300		38,000
Lease Intangibles [Member] | Assets Held-for-sale [Member]
Long lived assets held for sale [Abstract]
Accumulated depreciation and amortization	29,800		15,500
Leases, Acquired-in-Place, Market Adjustment [Member]
Long lived assets held for sale [Abstract]
Acquired below-market leases, net	14,381		16,984
Accumulated Amortization	-42,023		-42,621
Leases, Acquired-in-Place, Market Adjustment [Member] | Assets Held-for-sale [Member]
Long lived assets held for sale [Abstract]
Accumulated Amortization	3,900		3,200
Subsequent Event [Member]
Long lived assets held for sale [Abstract]
Contract Sale Price				$190,800	$53,800

Investments_in_Unconsolidated_2

Investments in Unconsolidated Entities (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Investments in unconsolidated entities
Amount of investment	$39,422,000		$39,885,000
Equity in operations of investments	243,000	88,000
Wanamaker Building
Investments in unconsolidated entities
Ownership Interest (as a percent)	60.00%
Amount of investment	38,182,000		38,609,000
Paces West
Investments in unconsolidated entities
Ownership Interest (as a percent)	10.00%
Amount of investment	1,240,000		1,276,000
Unconsolidated entities
Investments in unconsolidated entities
Distributions from investments	$600,000	$400,000

Real_Estate_Under_Development_

Real Estate Under Development (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Real Estate Under Development [Abstract]
Development costs capitalized	$2	$9
Interest costs capitalized	0.3	1
Available borrowings under construction loan	66
Draws on construction loan	$50.80

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Interest Expense [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$471	$0
Interest Rate Swap [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	-4,556	0
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liability	-5,345		-789
Swap Number One [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	125,000
Derivative, Fixed Interest Rate	1.68%
Swap Number Two [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	125,000
Derivative, Fixed Interest Rate	1.69%
Swap Number Three [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	125,000
Derivative, Fixed Interest Rate	1.76%
Swap Number Four [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	$150,000
Derivative, Fixed Interest Rate	1.77%

Derivative_Instruments_and_Hed3

Derivative Instruments and Hedging Activities (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Debt Instrument, by Type [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$6.10
Period Over Which Default Must be Remedied	30 days
Derivative, Net Liability Position, Aggregate Fair Value	5.4
Derivative, Termination value	5.4
Recourse Debt [Member]
Debt Instrument, by Type [Line Items]
Minimum amount of debt default that could cause derivative obligations to also be in default	10
Non-Recourse Debt [Member]
Debt Instrument, by Type [Line Items]
Minimum amount of debt default that could cause derivative obligations to also be in default	$75

Notes_Payable_Details

Notes Payable (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Principal payments due in:
Total	$1,124,475,000	$1,194,085,000
Number of Real Estate Properties	34
Notes payable
Long-term debt
Debt bearing interest at variable rates	50,800,000
Stated annual interest rate, low end of range (as a percent)	2.28%
Stated annual interest rate, high end of range (as a percent)	6.22%
Effective weighted average interest rate (as a percent)	5.03%
Principal payments due in:
April - December 2015	121,317,000
2016	560,609,000
2017	130,021,000
2018	97,622,000
2019	126,723,000
Thereafter	88,396,000
Unamortized discount	-213,000
Total	1,124,475,000
Mezzanine Loan
Long-term debt
Debt Instrument, Interest Rate, Stated Percentage (as a percent)	9.80%
Assets Held-for-sale [Member]
Principal payments due in:
Total	$96,824,000	$97,257,000

Notes_Payable_Credit_Facility_

Notes Payable (Credit Facility) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
	property
Credit Facility
Maximum borrowings available under credit facility	$475
Line of Credit Facility, Revolving loan extension period	1 year
Maximum increased amount of revolving loans	225
Line of Credit Facility, Number of real estate properties held as collateral	10
Available borrowings	180.3
LIBOR interest index Period One	1 month
LIBOR interest index Period Two	3 months
LIBOR Interest Index Period Three	6 months
Line of Credit Facility, Interest Rate During Period	3.10%
Credit facility | Federal Funds Effective Rate
Credit Facility
Applicable margin (as a percent)	0.50%
Credit facility | Debt Instrument Variable Rate Base Libor [Member]
Credit Facility
Applicable margin (as a percent)	1.00%
Revolving Credit Facility [Member]
Credit Facility
Maximum borrowings available under credit facility	225
Line of Credit Facility, Fair Value of Amount Outstanding	96
Term Loan Facility [Member]
Credit Facility
Maximum borrowings available under credit facility	250
Line of Credit Facility, Fair Value of Amount Outstanding	$125
Minimum [Member]
Credit Facility
Line of Credit, applicable margin	0.45%
Maximum [Member]
Credit Facility
Line of Credit, applicable margin	2.30%

Equity_Details

Equity (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Limited Partnership Units and Series A Convertible Preferred Stock
Fair Value of Series A Convertible Preferred Stock	$4,626	$4,626
Tier OP
Limited Partnership Units and Series A Convertible Preferred Stock
Units of limited partnership interest held by third parties (in units)	432,586
Services Holdings
Limited Partnership Units and Series A Convertible Preferred Stock
Stock issued in exchange of surrender of non-participating and non-voting convertible preferred stock (in shares)	10,000

Equity_Stock_Plans_Details

Equity (Stock Plans) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014	Dec. 31, 2013
Stock Plans
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	1,149,887		767,559		711,376	423,325
Restricted stock units outstanding	83,043		37,407		83,043	37,407
Restricted Stock Units, vesting period	13 months
Restricted stock issued during period ( in shares)	640,865	[1]	450,065	[1]
Share-Based Compensation, restrictions lapsed, number of shares	-202,354	[2]	-105,831
Stock Issued during period, Value, Restricted Stock Award	$4.48		$4.20
Restricted stock units, vested	37,407
Share-Based Compensation, percentage of restrictions that lapse	25.00%
Number of years over which restrictions lapse	4 years
Shares Paid for Tax Withholding for Share Based Compensation	60,376		33,592
Equity Option [Member] | Maximum
Stock Plans
Term of options	10 years
Equity Option [Member] | Independent members of the board of directors
Stock Plans
Outstanding options (in shares)	75,000
Weighted average exercise price (in dollars per share)	$6.69
Exercisable period after the date of grant for the grants made in 2008 and thereafter	1 year
[1]	Shares issued in 2015 had a grant price of $4.48 per share. Shares issued in 2014 had a grant price of $4.20 per share.
[2]	60,376 and 33,592 of these shares were surrendered in 2015 and 2014, respectively, to pay withholding tax.

Related_Party_Arrangements_Det

Related Party Arrangements (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Apr. 01, 2015
Related party arrangements
Related Party Transaction, Amounts of Transaction	$7,876,000	$8,138,000
Expensed	7,316,000	7,643,000
Related Party Transaction, Costs Capitalized to Real Estate Under Development	0	207,000
Capitalized to building and improvements, net	560,000	288,000
Amount payable to related parties	2,257,000		2,041,000
BHT Advisors
Related party arrangements
Contract termination fee				2,700,000
Gross service charge payable multiplier to determine termination payment	0.75
Period over which services payable would be calculated	12 months
BHT Advisors, acquisition fees	100,000	207,000
BHT Advisors, cost of services provided	650,000	640,000
HPT Management
Related party arrangements
Gross Management and Oversight Fees Earned Multiplier to Derive Buyout Consideration	0.8
Period over which services payable would be calculated	12 months
HPT Management, property and construction management fees	2,870,000	2,794,000
HPT Management, reimbursement of costs and expenses	$4,256,000	$4,497,000

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Commitments and contingencies
Number of executives	5
Period of automatic continuation of term of employment	1 year
Notice period for non-renewal of term prior to the expiration of the initial term	60 days
Commitments for future tenant improvements and leasing commissions
Commitments and contingencies
Future tenant improvements and leasing commissions	39.5
Employment Agreements
Commitments and contingencies
Compensation expense if termination of employment without cause	12.5

Supplemental_Cash_Flow_Informa2

Supplemental Cash Flow Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Supplemental Cash Flow Elements [Abstract]
Interest paid, net of amounts capitalized	$14,842	$18,387
Income taxes paid	125	61
Non-cash investing activities:
Property and equipment additions in accounts payable and accrued liabilities	16,571	17,168
Amortization of deferred financing fees in building and improvements, net	84	0
Non-cash financing activities:
Financing costs in accrued liabilities and payables to related parties		0
Unrealized Gain (Loss) on Derivatives	$4,556	$0