Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unaudited quarterly financial data
Sales	$ 3,348,911	$ 3,245,653	$ 3,507,540	$ 2,979,626	$ 3,274,301	$ 3,468,835	$ 3,126,575	$ 2,802,891		$ 13,081,730	$ 12,672,602	$ 8,920,552
Gross profit	151,001	187,769	167,143	156,844	221,844	134,974	149,261	144,330		662,757	650,409	583,052
Operating income	20,682	50,877	37,875	29,774	82,201	8,144	27,619	79,207		139,208	197,171	119,784
Net income (loss)	(880)	14,893	14,371	6,794	52,170	(14,464)	6,022	58,675		35,178	102,403	57,117
Net income attributable to Global Partners LP	(828)	15,080	14,489	7,126	52,530	(14,080)	6,413	59,042		35,867	103,905	58,752
Limited partners' interest in net income	$ (2,824)	$ 13,003	$ 12,441	$ 5,140	$ 50,294	$ (15,062)	$ 6,303	$ 58,646		$ 27,760	$ 100,181	58,358
Basic net (loss) income per limited partner unit (in dollars per unit)	$ (0.08)	$ 0.38	$ 0.37	$ 0.15	$ 1.49	$ (0.44)	$ 0.19	$ 1.74		$ 0.82	$ 2.98
Diluted net (loss) income per limited partner unit (in dollars per unit)	(0.08)	0.38	0.36	0.15	1.47	(0.44)	0.19	1.73		0.81	2.95
Cash distributions per limited partner unit (in dollars per unit)	$ 0.5250	$ 0.5200	$ 0.5150	$ 0.5100	$ 0.5000	$ 0.4750	$ 0.4750	$ 0.4625		$ 2.07	$ 1.91
Lease exit and termination gain, ASC842						$ 3,500				$ 493		(16,194)
Long-lived asset impairment	$ 1,400	$ 600								2,022	$ 414	809
Loss on early extinguishment of debt		13,100								13,080
Net (gain) loss on sale and disposition of assets	$ (2,400)	$ 300	$ (1,100)	$ 500	$ 100	$ 900	$ 3,000	$ 1,900		$ (2,730)	5,880	(1,624)
Loss on trustee taxes								(52,600)	$ 16,200		$ (52,627)	$ 16,194
Increase (decrease) in deferred tax liability attributable to tax rate change								$ 52,600