Amortization of Debt Discount

No definition available.

Name:	hr_AmortizationofDebtDiscount
Namespace Prefix:	hr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amortization of Premium

+ References

No definition available.

+ Details

Name:	hr_AmortizationofPremium
Namespace Prefix:	hr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt Instrument, Number of Extension Options

+ References

No definition available.

+ Details

Name:	hr_DebtInstrumentNumberOfExtensionOptions
Namespace Prefix:	hr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Period of Extension Option

+ References

No definition available.

+ Details

Name:	hr_DebtInstrumentPeriodOfExtensionOption
Namespace Prefix:	hr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Extension fee levied when the maturity is extended by one year.

+ References

No definition available.

+ Details

Name:	hr_ExtensionFeesDebtInstrument
Namespace Prefix:	hr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility basis spread on variable rate.

+ References

No definition available.

+ Details

Name:	hr_LineOfCreditFacilityBasisSpreadOnVariableRate
Namespace Prefix:	hr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Forward Starting Swaps

+ References

No definition available.

+ Details

Name:	hr_NumberofForwardStartingSwaps
Namespace Prefix:	hr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Lenders Term Loan

+ References

No definition available.

+ Details

Name:	hr_NumberofLendersTermLoan
Namespace Prefix:	hr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

+ Details

Name:	us-gaap_AmortizationOfDebtDiscountPremium
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of amortization expense attributable to debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(8))
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

Name:	us-gaap_AmortizationOfFinancingCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6036836-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

+ Details

Name:	us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

Name:	us-gaap_DeferredFinanceCostsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of cash received during the period on settlement of a hedge.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeCashReceivedOnHedge
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

Name:	us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

+ Details

Name:	us-gaap_NumberOfInterestRateDerivativesHeld
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=hr_UnsecuredCreditFacilityDue2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_MediumTermNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=hr_TermLoandue2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=hr_SeniorNotesdue2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=hr_SeniorNotesdue2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=hr_SeniorNotesdue2028Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_MortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=hr_MortgageNotesPayableNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Notes and Bonds Payable - Narrative (Details)				12 Months Ended
Notes and Bonds Payable - Narrative (Details)	Jul. 29, 2016 extension_option	Jul. 05, 2016 USD ($)	Apr. 24, 2015 USD ($) swap_agreement	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) swap_agreement	Dec. 31, 2016 USD ($) swap_agreement	Jan. 30, 2018 USD ($) swap_agreement	Dec. 20, 2017 USD ($) swap_agreement	Dec. 18, 2017 Lender	Dec. 11, 2017 USD ($)	Feb. 28, 2014 USD ($) Lender	Mar. 26, 2013 USD ($)	Oct. 14, 2011 USD ($)
Debt Instrument [Line Items]
Number of interest rate swaps \| swap_agreement					2
Unsecured term loan outstanding				$ 1,355,115,000
Number of forward starting swaps \| swap_agreement						4
Line of Credit [Member] \| Unsecured Credit Facility [Member]
Debt Instrument [Line Items]
Unsecured credit facility													$ 700,000,000.0
Number of extension options \| extension_option	2
Period of extension option	6 months
Extension fees as percentage of aggregate commitments	0.075%
Facility fee on the aggregate amount of commitments				0.20%
Amount outstanding under Unsecured Credit Facility				$ 262,000,000.0
Weighted average interest rate (LOC)				3.50%
Remaining borrowing capacity				$ 438,000,000.0
Line of Credit [Member] \| Unsecured Credit Facility [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Facility fee on the aggregate amount of commitments				0.13%
Line of Credit [Member] \| Unsecured Credit Facility [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Facility fee on the aggregate amount of commitments				0.30%
Line of Credit [Member] \| Unsecured Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Percentage of interest in addition to LIBOR				1.00%
Contractual interest rates, basis spread on variable rate				1.00%
Line of Credit [Member] \| Unsecured Credit Facility [Member] \| LIBOR [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Percentage of interest in addition to LIBOR				0.83%
Line of Credit [Member] \| Unsecured Credit Facility [Member] \| LIBOR [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Percentage of interest in addition to LIBOR				1.55%
Medium-term Notes [Member] \| Term Loan due 2022 [Member]
Debt Instrument [Line Items]
Senior notes face value				$ 150,000,000	$ 150,000,000						$ 200,000,000.0
Number of lenders, term loan \| Lender									9		9
Amount of debt repaid		$ 50,000,000.0
Contractual interest rates, basis spread on variable rate				1.10%
Number of interest rate swaps \| swap_agreement							2	2
Derivative notional amount							$ 50,000,000.0
Derivative, fixed interest rate							2.46%
Unsecured term loan outstanding				$ 150,000,000.0
Interest rate yielded per annum upon issuance				3.53%
Amortization of debt issuance costs				$ 200,000	200,000	$ 200,000
Medium-term Notes [Member] \| Term Loan due 2022 [Member] \| Interest Rate Swap [Member]
Debt Instrument [Line Items]
Derivative notional amount								$ 25,000,000.0
Derivative, fixed interest rate								2.18%
Medium-term Notes [Member] \| Term Loan due 2022 [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate				0.90%
Medium-term Notes [Member] \| Term Loan due 2022 [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate				1.75%
Medium-term Notes [Member] \| Term Loan due 2022 [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Contractual interest rates, basis spread on variable rate				1.10%
Senior Notes [Member] \| Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Senior notes face value				$ 250,000,000	250,000,000							$ 250,000,000.0
Interest rate on senior notes				3.75%								3.75%
Unaccreted discount				$ 974,000	1,178,000							$ 2,100,000
Deferred finance costs, gross												$ 2,100,000
Interest rate yielded per annum upon issuance												3.95%
Amount of amortization included in interest expense on the Company's consolidated Statements of operations				200,000	200,000	200,000
Amortization of debt issuance costs				200,000	200,000	200,000
Senior Notes [Member] \| Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Senior notes face value			$ 250,000,000.0	$ 250,000,000	250,000,000
Interest rate on senior notes			3.875%	3.88%
Unaccreted discount			$ 200,000	$ 141,000	160,000
Deferred finance costs, gross			$ 2,300,000
Interest rate yielded per annum upon issuance			4.08%
Amortization of debt issuance costs				200,000	200,000	200,000
Number of forward starting swaps \| swap_agreement			4
Senior Notes [Member] \| Senior Notes due 2025 [Member] \| Interest Rate Swap [Member]
Debt Instrument [Line Items]
Settlement of swap agreements			$ 1,700,000
Senior Notes [Member] \| Senior Notes due 2028 [Member]
Debt Instrument [Line Items]
Senior notes face value				$ 300,000,000	300,000,000					$ 300,000,000.0
Interest rate on senior notes				3.63%						3.625%
Unaccreted discount				$ 2,319,000	2,529,000					$ 2,500,000
Deferred finance costs, gross										$ 2,700,000
Interest rate yielded per annum upon issuance										3.84%
Amount of amortization included in interest expense on the Company's consolidated Statements of operations				200,000
Amortization of debt issuance costs				$ 200,000
Mortgage Notes [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Interest rate on senior notes				3.30%
Mortgage Notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Interest rate on senior notes				6.90%
Mortgage Notes [Member] \| Mortgage notes payable [Member]
Debt Instrument [Line Items]
Senior notes face value				$ 143,115,000	154,916,000
Unaccreted discount				968,000	1,332,000
Amortization of debt issuance costs				100,000	100,000	200,000
Amortization of debt discount				400,000	300,000	300,000
Amortization of debt premium				$ 800,000	$ 700,000	$ 900,000
Mortgage Notes [Member] \| Mortgage notes payable [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Interest rate on senior notes				3.31%
Mortgage Notes [Member] \| Mortgage notes payable [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Interest rate on senior notes				6.88%