Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - Equity Component [Domain] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues:
Product	$ 288,736	$ 402,986	$ 508,867	$ 830,016
Service	66,604	53,450	128,481	101,957
Other	21,886	25,788	38,188	49,134
Total revenues	377,226	482,224	675,536	981,107
Expenses:
Costs of products sold, exclusive of depreciation and amortization shown below	244,158	368,527	436,230	753,640
Operating	60,800	59,424	113,890	110,202
General and administrative	22,917	21,850	55,227	40,586
Depreciation and amortization	24,674	22,062	48,408	45,699
Loss on disposal or impairment of long-lived assets, net	1,372	19,315	2,430	19,257
Total expenses	353,921	491,178	656,185	969,384
Earnings from equity method investments	23,903	19,187	44,462	34,149
Gain on issuance of common units by equity method investee	5,897	0	5,897	8,127
Operating income	53,105	10,233	69,710	53,999
Other expenses (income), net:
Interest expense	16,822	10,360	31,413	19,587
Foreign currency transaction loss (gain)	(295)	167	(814)	(516)
Other expense (income), net	(6,718)	18,962	(14,703)	17,915
Total other expenses, net	9,809	29,489	15,896	36,986
Income (loss) from continuing operations before income taxes	43,296	(19,256)	53,814	17,013
Income tax expense (benefit)	14,861	(6,672)	19,603	9,854
Income (loss) from continuing operations	28,435	(12,584)	34,211	7,159
Loss from discontinued operations, net of income taxes	(2)	0	(2)	(5)
Net income (loss)	28,433	(12,584)	34,209	7,154
Less: net income attributable to noncontrolling interests	5,136	5,025	9,446	11,250
Net income (loss) attributable to SemGroup	23,297	(17,609)	24,763	(4,096)
Other comprehensive income (loss), net of income taxes	5,520	6,685	(3,540)	3,713
Comprehensive income (loss)	33,953	(5,899)	30,669	10,867
Less: comprehensive income attributable to noncontrolling interests	5,136	5,025	9,446	11,250
Comprehensive income (loss) attributable to SemGroup	$ 28,817	$ (10,924)	$ 21,223	$ (383)
Net income (loss) attributable to SemGroup per common share (Note 11):
Basic	$ 0.53	$ (0.41)	$ 0.57	$ (0.10)
Diluted	$ 0.53	$ (0.41)	$ 0.56	$ (0.10)