Investment in Unconsolidated and Consolidated Joint Ventures Investment in Unconsolidated and Consolidated Joint Ventures - Condensed Statements of Operations and Balance Sheet Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Statement of Operations
Revenues	$ 35,636	$ 31,432	$ 101,406	$ 85,727
Earnings(Loss)	2,794	3,919	5,466	9,488
Equity in Earnings(Loss)	1,724	2,353	3,512	5,650
Balance Sheet Information
Joint Venture Assets	213,368		213,368		$ 200,109
Joint Venture Debt	(111,590)		(111,590)		(97,318)
Joint Venture Equity	95,286		95,286		99,265
TRC Equity	28,911		28,911		33,803
Petro Travel Plaza Holdings LLC
Statement of Operations
Revenues	31,983	28,225	89,215	76,277
Earnings(Loss)	3,267	3,938	7,790	9,067
Equity in Earnings(Loss)	1,960	2,363	4,674	5,440
Balance Sheet Information
Joint Venture Assets	65,177		65,177		68,652
Joint Venture Debt	(15,278)		(15,278)		(15,275)
Joint Venture Equity	47,077		47,077		51,287
TRC Equity	15,846		15,846		18,372
Five West Parcel
Statement of Operations
Revenues	703	701	2,121	2,185
Earnings(Loss)	222	234	722	783
Equity in Earnings(Loss)	111	117	361	392
Balance Sheet Information
Joint Venture Assets	15,845		15,845		16,614
Joint Venture Debt	(9,847)		(9,847)		(10,251)
Joint Venture Equity	5,790		5,790		6,043
TRC Equity	2,710		2,710		2,837
18-19 West LLC
Statement of Operations
Revenues	3	3	8	7
Earnings(Loss)	(25)	(32)	(79)	(104)
Equity in Earnings(Loss)	(12)	(17)	(39)	(53)
Balance Sheet Information
Joint Venture Assets	4,633		4,633		4,623
Joint Venture Debt	0		0		0
Joint Venture Equity	4,614		4,614		4,621
TRC Equity	1,733		1,733		1,741
TRCC/Rock Outlet Center
Schedule of Equity Method Investments [Line Items]
Non-cash tenant allowance amortization	400	500	1,400	1,400
Statement of Operations
Revenues	2,012	2,275	7,287	7,030
Earnings(Loss)	(61)	(58)	(1,152)	(95)
Equity in Earnings(Loss)	(30)	(29)	(576)	(48)
Balance Sheet Information
Joint Venture Assets	83,570		83,570		86,056
Joint Venture Debt	(49,235)		(49,235)		(50,712)
Joint Venture Equity	33,371		33,371		34,523
TRC Equity	8,622		8,622		9,198
TRC-MRC 1 LLC
Statement of Operations
Revenues	0	0	0	0
Earnings(Loss)	0	0	(2)	0
Equity in Earnings(Loss)	0	0	(1)	0
Balance Sheet Information
Joint Venture Assets	22,861		22,861		199
Joint Venture Debt	(16,150)		(16,150)		0
Joint Venture Equity	4,542		4,542		199
TRC Equity	0		0		224
TRC-MRC 2 LLC
Schedule of Equity Method Investments [Line Items]
Non-cash amortization related to in-place leases	1,000	300	3,000	200
Statement of Operations
Revenues	935	228	2,775	228
Earnings(Loss)	(609)	(163)	(1,813)	(163)
Equity in Earnings(Loss)	(305)	(81)	(907)	(81)
Balance Sheet Information
Joint Venture Assets	21,282		21,282		23,965
Joint Venture Debt	(21,080)		(21,080)		(21,080)
Joint Venture Equity	(108)		(108)		2,592
TRC Equity	0		0		1,431
Centennial
Statement of Operations
Revenues	179	36	180	311
Earnings(Loss)	9	$ (57)	(308)	$ (298)
Balance Sheet Information
Joint Venture Assets	87,966		87,966		86,099
Joint Venture Debt	0		0		0
Joint Venture Equity	$ 86,897		$ 86,897		$ 85,281