Assets Held for Sale - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($) Property Store	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) Property Store	Sep. 30, 2016 USD ($)	Dec. 31, 2016 Store
Long Lived Assets Held-for-sale [Line Items]
Gain (loss) on sales of assets, net	$ 2,371	$ 631	$ 2,013	$ 525
Contributions from parent company			$ 329
Properties Disposed Upon FTC's Requirement [Member]
Long Lived Assets Held-for-sale [Line Items]
Number of properties sold | Property	2		2
Consideration received on property sale	$ 6,700		$ 6,700
Gain (loss) on sales of assets, net	$ 2,200		$ 2,200
DMR [Member]
Long Lived Assets Held-for-sale [Line Items]
Number of properties sold | Property	28		28
Consideration received on property sale	$ 16,600		$ 16,600
Gain (loss) on sales of assets, net	(500)		(500)
Escrow deposit	$ 3,000		$ 3,000
Additional properties under escrow | Property	3		3
Couche-Tard [Member] | Properties Disposed Upon FTC's Requirement [Member]
Long Lived Assets Held-for-sale [Line Items]
Contributions from parent company	$ 300		$ 300
DMS [Member]
Long Lived Assets Held-for-sale [Line Items]
Earn-out payment receivable	$ 800		$ 800
Assets Held-for-sale
Long Lived Assets Held-for-sale [Line Items]
Number of Stores | Store	4		4		4