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
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Statement of Operations
Revenues	$ 30,610	$ 27,046
Earnings(Loss)	161	2,452
Equity in Earnings(Loss)	228	1,455
Balance Sheet Information
Assets	205,278		$ 200,109
Debt	(96,968)		(97,318)
Equity	103,165		99,265
Equity	33,692		33,803
Petro Travel Plaza Holdings LLC
Statement of Operations
Revenues	26,407	23,954
Earnings(Loss)	1,502	2,291
Equity in Earnings(Loss)	901	1,375
Balance Sheet Information
Assets	69,921		68,652
Debt	(15,276)		(15,275)
Equity	52,789		51,287
Equity	19,273		18,372
Five West Parcel
Statement of Operations
Revenues	716	790
Earnings(Loss)	269	328
Equity in Earnings(Loss)	134	164
Balance Sheet Information
Assets	16,641		16,614
Debt	(10,116)		(10,251)
Equity	6,305		6,043
Equity	2,968		2,837
18-19 West LLC
Statement of Operations
Revenues	3	2
Earnings(Loss)	(24)	(43)
Equity in Earnings(Loss)	(13)	(22)
Balance Sheet Information
Assets	4,623		4,623
Debt	0		0
Equity	4,617		4,621
Equity	1,749		1,741
TRCC/Rock Outlet Center
Statement of Operations
Revenues	2,549	2,300
Earnings(Loss)	(1,009)	(124)
Equity in Earnings(Loss)	(505)	(62)
Balance Sheet Information
Assets	84,903		86,056
Debt	(50,227)		(50,712)
Equity	33,514		34,523
Equity	8,694		9,198
TRC-MRC 1 LLC
Statement of Operations
Revenues	0	0
Earnings(Loss)	(2)	0
Equity in Earnings(Loss)	(1)	0
Balance Sheet Information
Assets	5,972		199
Debt	(269)		0
Equity	4,102		199
Equity	0		224
TRC-MRC 2 LLC
Statement of Operations
Revenues	935	0
Earnings(Loss)	(575)	0
Equity in Earnings(Loss)	(288)	0
Balance Sheet Information
Assets	23,218		23,965
Debt	(21,080)		(21,080)
Equity	1,838		2,592
Equity	1,008		1,431
Centennial
Statement of Operations
Revenues	1	36
Earnings(Loss)	(110)	$ (57)
Balance Sheet Information
Assets	86,568		86,099
Debt			0
Equity	$ 86,071		$ 85,281