Investment in Unconsolidated and Consolidated Joint Ventures - Additional Information (Details)	3 Months Ended	12 Months Ended			15 Months Ended
	Jun. 30, 2013 USD ($) ft² member	Dec. 31, 2017 USD ($) a ft² joint_venture	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) a	Aug. 31, 2016 USD ($)	Sep. 30, 2013 USD ($)
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated joint ventures		$ 30,031,000	$ 33,803,000		$ 30,031,000
Equity in earnings (losses)		4,227,000	7,098,000	$ 6,324,000
Borrowings		114,272,000	97,318,000		$ 114,272,000
Distribution of earnings from unconsolidated joint ventures		$ 7,200,000	4,500,000	$ 7,200,000
Area of land to be developed (up to) (in acres) | a		270,000			270,000
Promissory Note
Schedule of Equity Method Investments [Line Items]
Face amount							$ 4,750,000
Line of Credit
Schedule of Equity Method Investments [Line Items]
Construction line of credit		$ 52,000,000			$ 52,000,000
Petro Travel Plaza Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Unconsolidated joint ventures, voting rights		50.00%
Ownership percentage		60.00%			60.00%
Investment in unconsolidated joint ventures		$ 17,422,000			$ 17,422,000
Borrowings		15,279,000	15,275,000		15,279,000
Majestic Realty Co.
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated joint ventures						$ 24,773,000
Investment in unconsolidated joint ventures		$ 0			0
Number of joint venture contracts | joint_venture		2
Area of building owned and leased | ft²		651,909
Majestic Realty Co. | Promissory Note
Schedule of Equity Method Investments [Line Items]
Face amount						$ 21,080,000
TRC-MRC 2, LLC
Schedule of Equity Method Investments [Line Items]
Borrowings		$ 21,080,000	21,080,000		21,080,000
Excess distributions resulting in deficit balance		$ 496,000			496,000
TRCC-East
Schedule of Equity Method Investments [Line Items]
Area of building owned and leased | ft²		480,480
Excess distributions resulting in deficit balance		$ 3,000			3,000
Distribution of earnings from unconsolidated joint ventures					1,952,000
Number of acres for development | ft²	326,000
TRC-MRC 1, LLC
Schedule of Equity Method Investments [Line Items]
Borrowings		19,433,000	0		19,433,000
Borrowings under joint venture		25,000,000			25,000,000
Rockefeller Joint Ventures
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated joint ventures		$ 12,609,000			$ 12,609,000
Number of joint venture contracts | joint_venture		3
Number of acres for development | a		91
Area of land to be developed (up to) (in acres) | a		500			500
Rockefeller Joint Ventures | Building Improvements
Schedule of Equity Method Investments [Line Items]
Number of joint venture contracts | joint_venture		2
Five West Parcel, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage		50.00%			50.00%
Area of building owned and leased | ft²		606,000
Borrowings		$ 9,711,000	10,251,000		$ 9,711,000
18-19 West, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage		50.00%			50.00%
Borrowings		$ 0	0		$ 0
Number of acres for development | a		61.5
TRCC/Rock Outlet Center, LLC
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated joint ventures	$ 87,000,000
Borrowings		$ 48,769,000	50,712,000		48,769,000
Construction loan percent of costs	60.00%
Equity contributions	40.00%
Number of members | member	2
Centennial Founders, LLC
Schedule of Equity Method Investments [Line Items]
Borrowings		0	$ 0		0
Reduction of noncontrolling interest in joint venture		$ 11,039,000			$ 11,039,000
Consolidated joint venture, ownership interest		89.28%			89.28%