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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Aug. 31, 2016	Dec. 31, 2015
Statement of Operations
Revenues			$ 85,727	$ 87,764
Total revenues	$ 13,079	$ 11,946	32,881	35,579
Net income (loss)			9,487	8,099
Net income (loss)	317	(811)	784	1,167
Partner’s share of net income (loss)			3,837	3,238
Net income attributable to parent	324	(788)	845	1,235
Equity in earnings (loss)			5,650	4,861
Equity in earnings of unconsolidated joint ventures, net	2,353	$ 2,055	5,650	4,861
Balance Sheet Information
Current assets	19,938		19,938			$ 20,046
Current assets, consolidated	51,132		51,132			48,893
Real Estate	162,377		162,377			135,459
Real Estate, consolidated	45,896		45,896			44,469
Other assets	16,980		16,980			20,275
Long-term debt	(97,963)		(97,963)			(77,255)
Other liabilities	(4,289)		(4,289)			(4,071)
Net assets	97,043		97,043			94,454
Petro Travel Plaza Holdings
Statement of Operations
Revenues			76,277	78,483
Net income (loss)			9,067	8,119
Partner’s share of net income (loss)			3,627	3,248
Equity in earnings (loss)			5,440	4,871
Balance Sheet Information
Current assets	10,960		10,960			12,013
Real Estate	54,977		54,977			52,296
Other assets	166		166			264
Long-term debt	(15,274)		(15,274)			(14,973)
Other liabilities	(2,552)		(2,552)			(2,890)
Net assets	48,277		48,277			46,710
Majestic
Statement of Operations
Revenues			228	0
Net income (loss)			(163)	0
Partner’s share of net income (loss)			(82)	0
Equity in earnings (loss)			(81)	0
Balance Sheet Information
Current assets	219		219			0
Real Estate	25,893		25,893			0
Other assets	(1,340)		(1,340)			0
Long-term debt					$ (20,926)	0
Other liabilities	(319)		(319)			0
Net assets	3,527		3,527			0
Rockefeller
Statement of Operations
Revenues			9,222	9,281
Net income (loss)			583	(20)
Partner’s share of net income (loss)			292	(10)
Equity in earnings (loss)			291	(10)
Balance Sheet Information
Current assets	8,759		8,759			8,033
Real Estate	81,507		81,507			83,163
Other assets	18,154		18,154			20,011
Long-term debt	(61,763)		(61,763)			(62,282)
Other liabilities	(1,418)		(1,418)			(1,181)
Net assets	45,239		45,239			47,744
Centennial-VIE | Primary Beneficiary
Statement of Operations
Total revenues			311	205
Net income (loss)			(298)	(175)
Net income attributable to parent			(17)	(45)
Equity in earnings of unconsolidated joint ventures, net			0	$ 0
Balance Sheet Information
Current assets, consolidated	32		32			230
Real Estate, consolidated	84,784		84,784			81,742
Other assets, consolidated	3		3			9
Long-term debt, consolidated	0		0			0
Other liabilities, consolidated	(590)		(590)			(754)
Net assets, consolidated	$ 84,229		$ 84,229			$ 81,227