Investment in Unconsolidated and Consolidated Joint Ventures Investment in Unconsolidated and Consolidated Joint Ventures - Condensed Statements of Operations and Balance Sheet Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Statement of Operations
Joint Venture Revenues	$ 34,235,000	$ 35,160,000	$ 62,065,000	$ 65,770,000
Joint Venture Earnings (Loss)	912,000	2,511,000	1,069,000	2,672,000
TRC Equity in Earnings (Loss)	652,000	1,560,000	819,000	1,788,000
Balance Sheet Information
Joint Venture Assets	219,931,000		219,931,000		$ 215,203,000
Joint Venture Debt	(119,540,000)		(119,540,000)		(114,273,000)
Joint Venture Equity	96,418,000		96,418,000		96,107,000
TRC Equity	30,742,000		30,742,000		30,031,000
Petro Travel Plaza Holdings, LLC
Statement of Operations
Joint Venture Revenues	30,384,000	30,825,000	55,061,000	57,232,000
Joint Venture Earnings (Loss)	1,957,000	3,021,000	2,844,000	4,523,000
TRC Equity in Earnings (Loss)	1,174,000	1,813,000	1,706,000	2,714,000
Balance Sheet Information
Joint Venture Assets	70,625,000		70,625,000		67,435,000
Joint Venture Debt	(15,281,000)		(15,281,000)		(15,280,000)
Joint Venture Equity	52,548,000		52,548,000		49,705,000
TRC Equity	19,128,000		19,128,000		17,422,000
Five West Parcel, LLC
Statement of Operations
Joint Venture Revenues	698,000	702,000	1,395,000	1,418,000
Joint Venture Earnings (Loss)	226,000	231,000	417,000	500,000
TRC Equity in Earnings (Loss)	112,000	116,000	208,000	250,000
Balance Sheet Information
Joint Venture Assets	15,902,000		15,902,000		15,738,000
Joint Venture Debt	(9,442,000)		(9,442,000)		(9,711,000)
Joint Venture Equity	6,389,000		6,389,000		5,972,000
TRC Equity	3,010,000		3,010,000		2,802,000
18-19 West, LLC
Statement of Operations
Joint Venture Revenues	3,000	2,000	6,000	5,000
Joint Venture Earnings (Loss)	(26,000)	(30,000)	(53,000)	(54,000)
TRC Equity in Earnings (Loss)	(13,000)	(14,000)	(26,000)	(27,000)
Balance Sheet Information
Joint Venture Assets	4,652,000		4,652,000		4,704,000
Joint Venture Debt	0		0		0
Joint Venture Equity	4,652,000		4,652,000		4,704,000
TRC Equity	1,756,000		1,756,000		1,782,000
TRCC/Rock Outlet Center, LLC
Schedule of Equity Method Investments [Line Items]
Non-cash tenant allowance amortization	400,000	500,000	800,000	1,000,000
Statement of Operations
Joint Venture Revenues	2,032,000	2,726,000	3,507,000	5,275,000
Joint Venture Earnings (Loss)	(1,259,000)	(82,000)	(2,354,000)	(1,091,000)
TRC Equity in Earnings (Loss)	(629,000)	(41,000)	(1,177,000)	(546,000)
Balance Sheet Information
Joint Venture Assets	78,098,000		78,098,000		81,610,000
Joint Venture Debt	(47,798,000)		(47,798,000)		(48,769,000)
Joint Venture Equity	29,822,000		29,822,000		32,177,000
TRC Equity	6,848,000		6,848,000		8,025,000
TRC-MRC 1, LLC
Statement of Operations
Joint Venture Revenues	139,000	0	139,000	0
Joint Venture Earnings (Loss)	(101,000)	0	(102,000)	(2,000)
TRC Equity in Earnings (Loss)	(50,000)	0	(51,000)	(1,000)
Balance Sheet Information
Joint Venture Assets	26,510,000		26,510,000		25,380,000
Joint Venture Debt	(21,779,000)		(21,779,000)		(19,433,000)
Joint Venture Equity	4,439,000		4,439,000		4,541,000
TRC Equity	0		0		0
TRC-MRC 2, LLC
Schedule of Equity Method Investments [Line Items]
Non-cash amortization related to in-place leases	200,000	1,000,000	400,000	2,000,000
Statement of Operations
Joint Venture Revenues	979,000	905,000	1,957,000	1,840,000
Joint Venture Earnings (Loss)	115,000	(629,000)	317,000	(1,204,000)
TRC Equity in Earnings (Loss)	58,000	(314,000)	159,000	(602,000)
Balance Sheet Information
Joint Venture Assets	24,144,000		24,144,000		20,336,000
Joint Venture Debt	25,240,000		25,240,000		(21,080,000)
Joint Venture Equity	(1,432,000)		(1,432,000)		(992,000)
TRC Equity	0		0		0
Centennial
Statement of Operations
Joint Venture Revenues	(76,000)	0	11,000	1,000
Joint Venture Earnings (Loss)	(194,000)	$ (207,000)	(212,000)	$ (317,000)
Balance Sheet Information
Joint Venture Assets	90,811,000		90,811,000		89,721,000
Joint Venture Debt	0		0		0
Joint Venture Equity	$ 90,425,000		$ 90,425,000		$ 88,862,000