Semgroup (SEMG) 10-K 27 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Jan. 30, 2015
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2014
Entity Registrant Name	SemGroup Corporation
Entity Central Index Key	1489136
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Public Float		$3,333,280,930
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Class A [Member]
Entity Common Stock, Shares Outstanding			43,825,556
Class B
Entity Common Stock, Shares Outstanding			0

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$40,598	$79,351
Restricted cash	6,980	5,119
Accounts receivable (net of allowance of $3,260 and $3,661 at December 31, 2014 and 2013, respectively)	351,334	323,965
Receivable from affiliates	16,819	67,273
Inventories	43,532	44,295
Other current assets	20,017	14,011
Total current assets	479,280	534,014
Property, plant and equipment (net of accumulated depreciation of $245,629 and $188,720 at December 31, 2014 and 2013, respectively)	1,256,825	1,105,728
Equity method investments	577,920	565,124
Goodwill	58,326	62,021
Other intangible assets (net of accumulated amortization of $20,545 and $12,655 at December 31, 2014 and 2013, respectively)	173,065	174,838
Other noncurrent assets, net	44,386	28,889
Total assets	2,589,802	2,470,614
Current liabilities:
Accounts payable	257,177	254,467
Payable to affiliates	13,460	62,279
Accrued liabilities	92,694	83,429
Payables to pre-petition creditors	3,129	3,177
Warrant liability	0	58,134
Deferred revenue	23,688	25,538
Other current liabilities	1,474	12,153
Current portion of long-term debt	40	37
Total current liabilities	391,662	499,214
Long-term debt	767,092	615,088
Deferred income taxes	161,956	100,945
Other noncurrent liabilities	49,655	41,504
Commitments and contingencies (Note 17)
SemGroup Corporation owners’ equity:
Common stock, $0.01 par value (authorized - 100,000 shares; issued - 44,689 and 42,898 shares, respectively)	436	425
Additional paid-in capital	1,245,877	1,154,516
Treasury stock, at cost (862 and 437 shares, respectively)	-1,332	-613
Accumulated deficit	-68,332	-97,572
Accumulated other comprehensive loss	-27,141	-2,854
Total SemGroup Corporation owners’ equity	1,149,508	1,053,902
Noncontrolling interests in consolidated subsidiaries	69,929	159,961
Total owners’ equity	1,219,437	1,213,863
Total liabilities and owners’ equity	$2,589,802	$2,470,614

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Per Share data, unless otherwise specified
Allowance for doubtful accounts	$3,260	$3,661
Accumulated depreciation	245,629	188,720
Accumulated amortization on other intangible assets	$20,545	$12,655
Par value per share	$0.01	$0.01
Common stock shares authorized	100,000	100,000
Common stock shares issued	44,689	42,898
Treasury Stock, Shares	862	437

Consolidated_Statements_of_Ope

Consolidated Statements of Operations and Comprehensive Income (Loss) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Product	$1,780,314	$1,145,104	$953,738
Service	233,239	140,198	117,721
Other	109,026	141,714	166,038
Total revenues	2,122,579	1,427,016	1,237,497
Expenses:
Costs of products sold, exclusive of depreciation and amortization shown below	1,623,358	1,020,100	874,885
Operating	246,613	223,585	224,700
General and administrative	87,845	78,597	71,918
Depreciation and amortization	98,397	66,409	48,210
Loss (gain) on disposal or impairment of long-lived assets, net	-32,592	239	3,531
Total expenses	2,088,805	1,388,452	1,216,182
Earnings from equity method investments	64,199	52,477	36,036
Gain on issuance of common units by equity method investee	29,020	26,873	0
Operating income (loss)	126,993	117,914	57,351
Other expenses (income):
Interest expense	49,044	25,142	8,902
Foreign currency transaction loss (gain)	-86	-1,633	298
Other expense (income), net	-20,536	45,906	21,271
Total other expenses, net	28,422	69,415	30,471
Income from continuing operations before income taxes	98,571	48,499	26,880
Income tax expense (benefit)	46,513	-17,254	-2,078
Income from continuing operations	52,058	65,753	28,958
Income (loss) from discontinued operations, net of income taxes	-1	59	2,939
Net income	52,057	65,812	31,897
Less: net income attributable to noncontrolling interests	22,817	17,710	9,797
Net income (loss) attributable to SemGroup	29,240	48,102	22,100
Other comprehensive income (loss):
Currency translation adjustments	-20,551	-6,363	12,635
Other, net of income tax	-3,736	4,808	-59
Total other comprehensive income (loss)	-24,287	-1,555	12,576
Comprehensive income (loss)	27,770	64,257	44,473
Less: comprehensive income attributable to noncontrolling interests	22,817	17,710	9,797
Comprehensive income (loss) attributable to SemGroup	$4,953	$46,547	$34,676
Net income per common share (Note 19):
Basic	$0.69	$1.14	$0.53
Diluted	$0.68	$1.13	$0.52

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Owners' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]
In Thousands
Beginning Balance at Dec. 31, 2011	$978,665	$418	$1,032,365	$0	($167,812)	($13,875)	$127,569
Net income (loss)	31,897	0	0	0	22,100	0	9,797
Other comprehensive income (loss), net of income taxes	12,576	0	0	0	0	12,576	0
Distributions to noncontrolling interests	-8,502	0	0	0	0	0	-8,502
Non-cash equity compensation	6,503	0	6,195	0	0	0	308
Warrants exercised	631	0	631	0	0	0	0
Issuance of common stock under compensation plans	0	2	-2	0	0	0	0
Repurchase of common stock	-242	0	0	-242	0	0	0
Other	0	0	0	0	38	0	-38
Ending Balance at Dec. 31, 2012	1,021,528	420	1,039,189	-242	-145,674	-1,299	129,134
Net income (loss)	65,812	0	0	0	48,102	0	17,710
Other comprehensive income (loss), net of income taxes	-1,555	0	0	0	0	-1,555	0
Distributions to noncontrolling interests	-17,647	0	0	0	0	0	-17,647
Non-cash equity compensation	7,330	0	6,524	0	0	0	806
Warrants exercised	21,379	4	21,375	0	0	0	0
Issuance of common stock under compensation plans	0	1	-1	0	0	0	0
Repurchase of common stock	-371	0	0	-371	0	0	0
Net proceeds from issuance of Rose Rock Midstream, L.P. common units	210,226	0	0	0	0	0	210,226
Transfer of SemCrude Pipeline interest to Rose Rock	-67,291	0	112,929	0	0	0	-180,220
Dividends paid	-25,429	0	-25,429	0	0	0	0
Unvested dividend equivalent rights	-119	0	-71	0	0	0	-48
Ending Balance at Dec. 31, 2013	1,213,863	425	1,154,516	-613	-97,572	-2,854	159,961
Net income (loss)	52,057	0	0	0	29,240	0	22,817
Other comprehensive income (loss), net of income taxes	-24,287	0	0	0	0	-24,287	0
Distributions to noncontrolling interests	-28,494	0	0	0	0	0	-28,494
Non-cash equity compensation	8,262	0	7,319	0	0	0	943
Warrants exercised	73,017	9	73,008	0	0	0	0
Issuance of common stock under compensation plans	2,172	2	2,170	0	0	0	0
Repurchase of common stock	-719	0	0	-719	0	0	0
Transfer of SemCrude Pipeline interest to Rose Rock	-31,930	0	53,243	0	0	0	-85,173
Dividends paid	-44,206	0	-44,206	0	0	0	0
Unvested dividend equivalent rights	-298	0	-173	0	0	0	-125
Ending Balance at Dec. 31, 2014	$1,219,437	$436	$1,245,877	($1,332)	($68,332)	($27,141)	$69,929

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income (loss)	$52,057	$65,812	$31,897
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net unrealized (gain) loss related to derivative instruments	-1,734	-974	1,196
Depreciation and amortization	98,397	66,409	48,646
Loss (gain) on disposal or impairment of long-lived assets, net	-32,592	216	6,621
Equity earnings from investments	-64,199	-52,477	-36,036
Gain on issuance of common units by equity method investee	-29,020	-26,873	0
Gain on sale of common units of equity method investee	-34,211	0	0
Distributions from equity investments	85,261	63,651	36,440
Amortization and write down of debt issuance costs	3,632	2,732	2,425
Deferred tax expense (benefit)	36,148	-36,274	-11,818
Non-cash compensation expense	8,386	7,330	6,503
Excess tax benefit from equity-based awards	-1,650	0	0
(Gain) loss on fair value of warrants	13,423	46,433	21,310
Provision for uncollectible accounts receivable, net of recoveries	360	-372	-315
Inventory valuation adjustment	5,667	0	0
Currency (gain) loss	-86	-1,633	298
Changes in operating assets and liabilities (Note 23)	-23,365	39,861	-14,283
Net cash provided by operating activities	181,658	173,409	79,642
Cash flows from investing activities:
Capital expenditures	-270,506	-215,609	-119,319
Proceeds from sale of long-lived assets	4,445	1,279	2,641
Investments in non-consolidated subsidiaries	-71,131	-173,868	-78,253
Payments to acquire businesses	-44,508	-362,456	0
Proceeds from sale of common units of equity method investee	79,741	0	0
Proceeds from sale of non-consolidated affiliate	0	0	3,500
Proceeds from the sale of SemStream assets	0	0	12,250
Distributions from equity method investments in excess of equity in earnings	11,734	12,246	17,290
Net cash provided by (used in) investing activities	-290,225	-738,408	-161,891
Cash flows from financing activities:
Debt issuance costs	-8,686	-14,936	-707
Borrowings on debt and other obligations	1,254,244	1,268,474	318,000
Principal payments on debt and other obligations	-1,102,272	-859,412	-222,066
Distributions to noncontrolling interests	-28,494	-17,647	-8,502
Proceeds from warrant exercises	1,451	225	0
Repurchase of common stock	-719	-371	-242
Dividends paid	-44,206	-25,429	0
Proceeds from issuance of common stock under employee stock purchase plan	340	0	0
Excess tax benefit from equity-based awards	1,650	0	0
Proceeds from issuance of Rose Rock Midstream, L.P. common units, net of offering costs	0	210,226	0
Net cash provided by (used in) financing activities	73,308	561,130	86,483
Effect of exchange rate changes on cash and cash equivalents	-3,494	3,191	-610
Change in cash and cash equivalents	-38,753	-678	3,624
Change in cash and cash equivalents included in discontinued operations	0	0	2,792
Change in cash and cash equivalents from continuing operations	-38,753	-678	6,416
Cash and cash equivalents at beginning of period	79,351	80,029	73,613
Cash and cash equivalents at end of period	$40,598	$79,351	$80,029

Overview

Overview	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview	OVERVIEW
	SemGroup Corporation is a Delaware corporation headquartered in Tulsa, Oklahoma that provides diversified services for end-users and consumers of crude oil, natural gas, natural gas liquids, refined products and asphalt.
	The accompanying consolidated financial statements include the activities of SemGroup Corporation and its subsidiaries. The terms “we,” “our,” “us,” “the Company” and similar language used in these notes to consolidated financial statements refer to SemGroup Corporation and its subsidiaries.
	At December 31, 2014, our reportable segments include the following:
	•	Crude conducts crude oil transportation, storage, terminalling, gathering and marketing operations in the United States. Crude’s assets include:
	•	the 2% general partner interest and a 56.8% limited partner interest in Rose Rock Midstream, L.P. ("Rose Rock"), which owns an approximate 570-mile crude oil pipeline network in Kansas and Oklahoma, a crude oil gathering, storage and marketing business in the Bakken Shale in North Dakota and Montana, a crude oil storage facility in Cushing, Oklahoma with a capacity of 7.6 million barrels and a crude oil trucking fleet of over 255 transport trucks and 275 trailers;
	•	a 51% ownership interest (through our interest in Rose Rock) in White Cliffs Pipeline, L.L.C. ("White Cliffs"), which owns a 527-mile pipeline, consisting of two 12-inch common carrier, crude oil pipelines, that transports crude oil from Platteville, Colorado to Cushing, Oklahoma (the "White Cliffs Pipeline"); and
	•	a 50% ownership interest in Glass Mountain Pipeline LLC ("Glass Mountain"), which owns a 210-mile crude oil pipeline in western and north central Oklahoma ("the Glass Mountain Pipeline").
	•	SemStream, which owns 6,652,101 common units representing 7.5% of the total limited partner interests, as of September 30, 2014, in NGL Energy Partners LP ("NGL Energy") (NYSE: NGL), which owns and operates wholesale and retail propane storage and distribution assets, crude oil logistics and water treatment services in the United States, and a 11.78% interest in the general partner of NGL Energy. We report the results of our investment in NGL Energy under the equity method on a one-quarter lag (Note 5).
	•	SemCAMS, which provides natural gas gathering and processing services in Alberta, Canada. SemCAMS owns working interests in, and operates, four natural gas processing plants with a combined operating capacity of 695 million cubic feet per day.
	•	SemGas, which provides natural gas gathering and processing services in the United States. SemGas owns and operates gathering systems and four processing plants in Oklahoma, Texas and Kansas with 388 million cubic feet per day of capacity.
	•	SemLogistics, which provides refined product and crude oil storage services in the United Kingdom. SemLogistics owns a facility in Wales that has multi-product storage capacity of approximately 8.7 million barrels.
	•	SemMexico, which purchases, produces, stores, and distributes liquid asphalt cement products in Mexico. SemMexico operates an in-country network of fourteen asphalt cement terminals and modification facilities, one toll manufacturing facility and one portable rail unloading facility.

Consolidation_And_Basis_Of_Pre

Consolidation And Basis Of Presentation	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation and Basis of Presentation	CONSOLIDATION AND BASIS OF PRESENTATION
	The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States.
	Consolidated subsidiaries
	Our consolidated financial statements include the accounts of our controlled subsidiaries, including Rose Rock. All significant transactions between our consolidated subsidiaries have been eliminated. Outside ownership interests in consolidated subsidiaries are reported as noncontrolling interests in the consolidated financial statements.
	Proportionally consolidated assets
	Our SemCAMS segment owns undivided interests in certain natural gas gathering and processing assets, for which we record only our proportionate share of the assets on the consolidated balance sheets. The net book value of the property, plant and equipment recorded by us associated with these undivided interests is approximately $209.8 million at December 31, 2014. We serve as operator of these facilities and incur the costs of operating the facilities (recorded as operating expenses in the consolidated statements of operations) and charge the other owners for their proportionate share of the costs (recorded as other revenue in the consolidated statements of operations).
	Equity method investments
	We own a 51% interest in White Cliffs. The other owners have substantive rights to participate in the management of White Cliffs. Because of this, we account for it under the equity method. In 2014 and 2013, we sold our interest in SemCrude Pipeline, which holds the 51% interest in White Cliffs, to our consolidated subsidiary Rose Rock. We will continue to account for our interest under the equity method. No gain was recorded on the transaction as it was between entities under common control.
	We own general partner and limited partner interests in NGL Energy which we account for under the equity method.
	We own a 50% interest in Glass Mountain which we account for under the equity method.
	Discontinued operations
	During 2012, we completed the disposition of SemStream's residential propane supply business in Arizona, which is accounted for as a discontinued operation (Note 8).

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Signifcant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	USE OF ESTIMATES—The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts and disclosures in the financial statements. Our significant estimates include, but are not limited to: (1) allowances for doubtful accounts receivable; (2) estimated useful lives of assets, which impact depreciation; (3) estimated fair values of long-lived assets used in impairment tests; (4) fair values of derivative instruments; (5) valuation allowances for deferred tax assets; and (6) accrual and disclosure of contingent losses. Although management believes these estimates are reasonable, actual results could differ materially from these estimates.
	CASH AND CASH EQUIVALENTS—Cash includes currency on hand and demand and time deposits with banks or other financial institutions. Cash equivalents include highly liquid investments with maturities of three months or less at the date of purchase. Balances at financial institutions may exceed federally insured limits.
	RESTRICTED CASH—At December 31, 2014, we had not yet completed the process of disbursing funds held in reserve accounts to settle pre-petition claims related to our predecessor's bankruptcy. Of the restricted cash balance of $7.0 million at December 31, 2014, approximately $3.8 million is restricted for this purpose. See payables to pre-petition creditors below.
	ACCOUNTS RECEIVABLE—Accounts receivable are reported net of the allowance for doubtful accounts. Our assessment of the allowance for doubtful accounts is based on several factors, including the overall creditworthiness of our customers, existing economic conditions, and the amount and age of past due accounts. We enter into netting arrangements with certain counterparties to help mitigate credit risk. Receivables subject to netting are presented as gross receivables (with the related accounts payable also presented gross) until such time as the balances are settled. Receivables are considered past due if full payment is not received by the contractual due date. Past due accounts are written off against the allowance for doubtful accounts only after all collection attempts have been exhausted.
	INVENTORIES—Inventories primarily consist of natural gas and natural gas liquids, crude oil, and asphalt. Inventories are valued at the lower of cost or market, with cost generally determined using the weighted-average method. The cost of inventory includes applicable transportation costs.
	We enter into exchanges with third parties whereby we acquire products that differ in location, grade, or delivery date from products we have available for sale. These exchanges are valued at cost, and although a transportation, location or product differential may be recorded, generally no gain or loss is recognized.
	PROPERTY, PLANT AND EQUIPMENT—Property, plant and equipment is recorded at cost. We capitalize costs that extend or increase the future economic benefits of property, plant and equipment, and expense maintenance costs that do not. When assets are disposed of, their cost and related accumulated depreciation are removed from the balance sheet, and any resulting gain or loss is recorded as a gain or loss on disposal or impairment of long-lived assets in the consolidated statements of operations.
	Our SemCAMS segment operates plants which periodically undergo planned major maintenance activities, typically occurring every four to five years.  Planned major maintenance projects that do not increase the overall life or capacity of the related assets are recorded in operating expense as incurred, whereas major maintenance activity costs that materially increase the life or capacity of the underlying assets are capitalized. When maintenance expenses are recoverable from the producers who use the plants, they are recorded as revenue, and typically include a 10% overhead fee.
	Depreciation is calculated primarily on the straight-line method over the following estimated useful lives:
	Pipelines and related facilities	10 – 31 years
	Storage and terminal facilities	10 – 25 years
	Natural gas gathering and processing facilities	10 – 31 years
	Trucking equipment and other	3 – 7 years
	Office property and equipment	3 – 31 years
	Construction in process is reclassified to the fixed asset categories above and depreciation commences once the asset has been placed in-service.
	LINEFILL—Pipelines and storage facilities generally require a minimum volume of product in the system to enable the system to operate. Such product, known as linefill, is generally not available to be withdrawn from the system. Linefill owned by us in facilities operated by us is recorded at historical cost, is included in property, plant and equipment in the consolidated balance sheets, and is not depreciated. We also own linefill in third-party facilities, which is included in inventory on the consolidated balance sheets.
	IMPAIRMENT OF LONG-LIVED ASSETS—We test long-lived asset groups for impairment when events or circumstances indicate that the net book value of the asset group may not be recoverable. We test an asset group for impairment by estimating the undiscounted cash flows expected to result from its use and eventual disposition. If the estimated undiscounted cash flows are lower than the net book value of the asset group, we then estimate the fair value of the asset group and record a reduction to the net book value of the assets and a corresponding impairment loss.
	GOODWILL—We test goodwill for impairment on an annual basis, or more often if circumstances warrant, by estimating the fair value of the asset group to which the goodwill relates and comparing this fair value to the net book value of the asset group. If fair value is less than net book value, we estimate the implied fair value of goodwill, reduce the book value of the goodwill to the implied fair value, and record a corresponding impairment loss. Our policy is to test goodwill for impairment on October 1 of each year.
	INTANGIBLE ASSETS—Intangible assets are stated at cost, net of accumulated amortization, which is recorded on a straight-line or accelerated basis over the life of the asset. We review amortizable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. If such a review should indicate that the carrying amount of amortizable intangible assets is not recoverable, we reduce the carrying amount of such assets to fair value.
	EQUITY METHOD INVESTMENTS—We account for an investment under the equity method when we have significant influence over, but not control of, the significant operating decisions of the investee. Under the equity method, we record in the consolidated statements of operations our share of the earnings or losses of the investee, with a corresponding adjustment to the investment balance on our consolidated balance sheet. When we receive a distribution from an equity method investee, we record a corresponding reduction to the investment balance. When an equity method investee issues additional ownership interests which dilute our ownership interest, we recognize a gain or loss in our consolidated statements of operations.
	For equity method investments for which we do not expect financial information to be consistently available on a timely basis to apply the equity method currently, our policy is to apply the equity method consistently on a one-quarter lag.
	DEBT ISSUANCE COSTS—Costs incurred in connection with the issuance of long-term debt are reported as other noncurrent assets and are amortized to interest expense using the straight-line method over the term of the related debt. Use of the straight-line method of amortization does not differ materially from the “effective interest” method.
	COMMODITY DERIVATIVE INSTRUMENTS—We generally record the fair value of commodity derivative instruments on the consolidated balance sheets and the change in fair value as an increase or decrease to product revenue.
	As shown in Note 14, the fair value of commodity derivatives at December 31, 2014 and 2013 are recorded to other current assets or other current liabilities on the consolidated balance sheets. Related margin deposits are recorded to other current assets or other current liabilities on the consolidated balance sheets. Margin deposits are not generally netted against derivative assets or liabilities.
	The fair value of a derivative contract is determined based on the nature of the transaction and the market in which the transaction was executed. Quoted market prices, when available, are used to value derivative transactions. In situations where quoted market prices are not readily available, we estimate the fair value using other valuation techniques that reflect the best information available under the circumstances. Fair value measurements of derivative assets include consideration of counterparty credit risk. Fair value measurements of derivative liabilities include consideration of our creditworthiness.
	We have elected “normal purchase” and “normal sale” treatment for certain commitments to purchase or sell petroleum products at future dates. This election is only available when a transaction that would ordinarily meet the definition of a derivative but instead is expected to result in physical delivery of product over a reasonable period in the normal course of business and is not expected to be net settled. Agreements accounted for under this election are not recorded at fair value; instead, the transaction is recorded when the product is delivered.
	PAYABLES TO PRE-PETITION CREDITORS—At December 31, 2014, we had not yet completed the process of disbursing funds held in reserve accounts to settle pre-petition claims related to our predecessor's bankruptcy. We recorded a liability of $3.1 million at December 31, 2014 associated with these obligations and a liability of $0.7 million which is associated with discontinued operations and is reported within other current liabilities. Cash is held in accounts restricted for this purpose which is included in Restricted Cash on the balance sheet. All pre-petition claims payable from these accounts have been settled and we expect to disburse the cash as soon as the accounts have been reconciled.
	CONTINGENT LOSSES—We record a liability for a contingent loss when it is probable that a loss has been incurred and the amount of the loss can be reasonably estimated. We record attorneys’ fees incurred in connection with a contingent loss at the time the fees are incurred. We do not record liabilities for attorneys’ fees that are expected to be incurred in the future.
	ASSET RETIREMENT OBLIGATIONS—Asset retirement obligations include legal or contractual obligations associated with the retirement of long-lived assets, such as requirements to incur costs to dispose of equipment or to remediate the environmental impacts of the normal operation of the assets. We record liabilities for asset retirement obligations when a known obligation exists under current law or contract and when a reasonable estimate of the value of the liability can be made.
	DISCONTINUED OPERATIONS—We classify a component of our business as a discontinued operation when we commit to a plan to sell the component and believe it is probable that a sale will be completed within one year. A component that is disposed of in a manner other than by sale is classified as discontinued when the component is actually disposed. Investments accounted for under the equity method, or the cost method, do not qualify for treatment as discontinued operations. A component that is disposed of may not qualify for treatment as a discontinued operation if we have significant continuing involvement in the operations of the component after the disposal.
	Once a component meets the requirements to be classified as a discontinued operation, previous financial statements are retrospectively adjusted to reflect the component as a discontinued operation for all periods presented. Income and losses of discontinued operations (excluding corporate general and administrative expense allocations) are combined into one line on the consolidated statements of operations. The cash flows from discontinued operations are not separately identified in the consolidated statements of cash flows.
	In April 2014, the FASB issued ASU 2014-08, "Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity," which raises the threshold for a disposal to qualify as a discontinued operation and requires new disclosures of both discontinued operations and certain other disposals that do not meet the definition of a discontinued operation. For public entities, this ASU is effective for fiscal years beginning on or after December 15, 2014, and interim periods within those years. The Company will adopt this guidance in the first quarter of 2015. The impact is not expected to be material.
	REVENUE RECOGNITION—Sales of product, as well as gathering and marketing revenues, are recognized at the time title to the product transfers to the purchaser, which typically occurs upon receipt of the product by the purchaser. Terminal and storage revenues are recognized at the time the service is performed. Revenue for the transportation of product is recognized upon delivery of the product to its destination. Certain revenue transactions are reported on a net basis, including derivative instruments considered held for trading purposes and certain buy/sell transactions (see “Purchases and Sales of Inventory with the Same Counterparty”). Other revenue primarily represents operating cost recovery from working interest owners in certain processing plants and is recorded when earned in accordance with the terms of related agreements. Taxes collected from customers and remitted to governmental authorities are recorded on a net basis (excluded from revenue).
	In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers", which supersedes nearly all existing revenue recognition guidance under U.S. GAAP. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. ASU 2014-09 defines a five step process to achieve this core principle and, in doing so, more judgment and estimates may be required within the revenue recognition process than are required under existing U.S. GAAP.
	The standard is effective for annual periods beginning after December 15, 2016, and interim periods therein, using either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (ii) a retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures). We are currently evaluating the impact of our pending adoption of ASU 2014-09 on our consolidated financial statements and have not yet determined the method by which we will adopt the standard in 2017.
	COSTS OF PRODUCTS SOLD—Costs of products sold consists of the cost to purchase the product, the cost to transport the product to the point of sale, and the cost to store the product until it is sold.
	PURCHASES AND SALES OF INVENTORY WITH THE SAME COUNTERPARTY—We routinely enter into transactions to purchase inventory from, and sell inventory to, the same counterparty. Such transactions that are entered into in contemplation of one another are recorded on a net basis.
	CURRENCY TRANSLATION—The consolidated financial statements are presented in U.S. dollars. Our segments operate in four countries, and each segment has identified a “functional currency,” which is the primary currency in the environment in which the segment operates. The functional currencies include the U.S. dollar, the Canadian dollar, the British pound sterling, and the Mexican peso.
	At the end of each reporting period, the assets and liabilities of each segment are translated from its functional currency to U.S. dollars using the exchange rate at the end of the month. The monthly results of operations of each segment are generally translated from its functional currency to U.S. dollars using the average exchange rate during the month. Changes in exchange rates result in currency translation gains and losses, which are recorded within other comprehensive income (loss).
	Certain segments also enter into transactions in currencies other than their functional currencies. At the end of each reporting period, each segment re-measures the related receivables, payables, and cash to its functional currency using the exchange rate at the end of the period. Changes in exchange rates between the time the transactions were entered into and the end of the reporting period result in currency transaction gains or losses, which are recorded in the consolidated statements of operations.
	INCOME TAXES—Deferred income taxes are accounted for under the liability method, which takes into account the differences between the basis of the assets and liabilities for financial reporting purposes and amounts recognized for income tax purposes. We record valuation allowances on deferred tax assets when, in the opinion of management, it is more likely than not that the asset will not be recovered.
	We monitor uncertain tax positions and we recognize tax benefits only when management believes the relevant tax positions would more likely than not be sustained upon examination. We record any interest and any penalties related to income taxes within income tax expense in the consolidated statements of operations.
	In July 2013, the FASB issued ASU 2013-11, "Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists," which requires an unrecognized tax benefit to be classified as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except in certain circumstances. For public entities, this ASU is effective for fiscal years beginning on or after December 15, 2013, and interim periods within those years. The Company adopted this guidance in the first quarter of 2014. The impact was not material.
	RECLASSIFICATIONS—Certain reclassifications have been made to conform prior year balances to the current year presentation.
	PENSION BENEFITS—Pension cost and obligations are actuarially determined and are affected by assumptions including expected return on plan assets, discount rates, compensation increases, and employee turnover rates. We evaluate our assumptions periodically and make adjustments to these assumptions and the recorded liability as necessary. Actuarial gains or losses are amortized on a straight-line basis over the expected remaining service life of employees in the pension plan.
	EQUITY-BASED COMPENSATION—We grant certain of our employees equity-based compensation awards which vest contingent on continued service of the recipient and, in some cases, on their achievement of specific performance targets. We record compensation expense for these outstanding awards over applicable service or performance periods based on their grant date fair value with a corresponding increase to additional paid-in capital. The expense to be recorded over the life of the awards is discounted for expected forfeitures during the vesting period.
	NONCONTROLLING INTERESTS IN CONSOLIDATED SUBSIDIARIES—Noncontrolling interests represents third-party limited partner unitholders' interests in our consolidated subsidiary, Rose Rock. Rose Rock allocates net income to its limited partners based on the distributions pertaining to the current period's available cash as defined by Rose Rock's partnership agreement. After adjusting for the appropriate period's distributions, the remaining undistributed earnings or excess distributions over earnings, if any, are allocated to Rose Rock's general partner, limited partners and participating securities in accordance with the contractual terms of Rose Rock's partnership agreement and as further prescribed under the two-class method. Incentive distribution rights do not participate in undistributed earnings.
	COMPREHENSIVE INCOME (LOSS) AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)—Comprehensive income (loss) is defined as a change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources and includes all changes in equity during a period except those resulting from investments by owners and distributions to owners. Our comprehensive income (loss) consists of currency translation adjustments, changes in the funded status of pension benefit plans and changes in the fair value of interest rate swaps.
	On March 4, 2013, the FASB issued ASU 2013-05, "Parent's Accounting for the Cumulative Translation Adjustment Upon Derecognition of Certain Subsidiaries or Groups of Assets Within a Foreign Entity or of an Investment in a Foreign Entity - a consensus of the FASB Emerging Issues Task Force”, which indicates that the entire amount of a cumulative translation adjustment ("CTA") related to an entity's investment in a foreign entity should be released when there has been a:
	•	sale of a subsidiary or group of net assets within a foreign entity and the sale represents the substantially complete liquidation of the investment in the foreign entity;
	•	loss of a controlling financial interest in an investment in a foreign entity (i.e., the foreign entity is deconsolidated); or
	•	step acquisition for a foreign entity (i.e., when an entity has changed from applying the equity method for an investment in a foreign entity to consolidating the foreign entity).
	The ASU does not change the requirement to release a pro rata portion of the CTA of the foreign entity into earnings for a partial sale of an equity method investment in a foreign entity. For public entities, this ASU is effective for fiscal years beginning on or after December 15, 2013, and interim periods within those years. The Company adopted this guidance in the first quarter of 2014. The impact was not material.

Rose_Rock_Midstream_LP

Rose Rock Midstream, L.P.	12 Months Ended
	Dec. 31, 2014
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Rose Rock Midstream, L.P.	ROSE ROCK MIDSTREAM, L.P.
	At December 31, 2014, we owned the 2% general partner interest and a 56.8% limited partner interest that included 6,814,709 common units, 8,389,709 subordinated units and 3,750,000 Class A units of Rose Rock. We also own certain incentive distribution rights, which are described below. We control the operations of Rose Rock through our ownership of the general partner interest, and we continue to consolidate Rose Rock. The outside ownership interests in Rose Rock are reflected in “noncontrolling interests in consolidated subsidiaries” on our consolidated balance sheets. The portion of the net income of Rose Rock that is attributable to outside owners is reflected within “net income attributable to noncontrolling interests” in our consolidated statements of operations and comprehensive income.
	Rose Rock intends to pay a minimum quarterly distribution of $0.3625 per unit to the extent it has sufficient available cash, as defined in Rose Rock’s partnership agreement. Rose Rock’s partnership agreement requires Rose Rock to distribute all of its available cash each quarter in the following manner:
		Total Quarterly Distributions												Marginal Percentage
		Per Unit Target Amount												Interest in Distributions
														Unitholders			General			Incentive
																	Partner			Distribution
																				Rights
	Minimum Quarterly Distributions									$	0.3625			98	%		2	%		—
	First Target Distribution	above		$	0.3625			up to		$	0.416875			98	%		2	%		—
	Second Target Distribution	above		$	0.416875			up to		$	0.453125			85	%		2	%		13	%
	Third Target Distribution	above		$	0.453125			up to		$	0.54375			75	%		2	%		23	%
	Thereafter							above		$	0.54375			50	%		2	%		48	%
	The following table shows the distributions paid related to the earnings for each of the following periods (in thousands, except for per unit amounts):
		Distribution				Distributions Paid
	Quarter Ended	Per Unit				SemGroup												Noncontrolling			Total
																		Interest			Distributions
						General			Incentive			Common			Subordinated			Common Units
						Partner			Distributions			Units			Units
	December 31, 2011	$	0.067		*	$	23		$	—		$	93		$	561		$	470		$	1,147
	March 31, 2012	$	0.3725			$	128		$	—		$	517		$	3,125		$	2,607		$	6,377
	June 30, 2012	$	0.3825			$	131		$	—		$	532		$	3,209		$	2,678		$	6,550
	September 30, 2012	$	0.3925			$	134		$	—		$	545		$	3,294		$	2,748		$	6,721
	December 31, 2012	$	0.4025			$	167		$	—		$	1,163		$	3,377		$	3,624		$	8,331
	March 31, 2013	$	0.43			$	179		$	41		$	1,242		$	3,607		$	3,872		$	8,941
	June 30, 2013	$	0.44			$	183		$	72		$	1,271		$	3,692		$	3,962		$	9,180
	September 30, 2013	$	0.45			$	232		$	127		$	1,301		$	3,775		$	6,189		$	11,624
	December 31, 2013	$	0.465			$	257		$	244		$	2,041		$	3,901		$	6,398		$	12,841
	31-Mar-14	$	0.495			$	278		$	488		$	2,173		$	4,153		$	6,811		$	13,903
	30-Jun-14	$	0.535			$	334		$	888		$	3,646		$	4,488		$	7,362		$	16,718
	30-Sep-14	$	0.575			$	377		$	1,835		$	3,918		$	4,824		$	7,912		$	18,866
	31-Dec-14	$	0.62		**	$	485		$	3,487		$	6,551		$	5,202		$	8,544		$	24,269
	*Minimum quarterly distribution for quarter ended December 31, 2011 was prorated for the period beginning immediately after the closing of Rose Rock’s IPO, December 14, 2011 through December 31, 2011.
	** The distribution to common unitholders related to earnings for the quarter ended December 31, 2014 was payable on February 13, 2015 to holders of record at February 3, 2015. As such, the Class A units, which converted to common units on January 1, 2015, were eligible for the distribution which is reflected in the amount paid to common unitholders.
	Certain summarized balance sheet information of Rose Rock is shown below (in thousands):
		31-Dec-14				31-Dec-13
	Cash	$	3,666			$	15,459
	Other current assets	270,224				306,128
	Property, plant and equipment, net	335,910				311,616
	Equity method investment	269,635				224,095
	Goodwill	36,116				28,322
	Other noncurrent assets	29,677				11,627
	Total assets	$	945,228			$	897,247
	Current liabilities	$	263,680			$	293,031
	Long-term debt	432,092				245,088
	Partners’ capital attributable to SemGroup	179,527				120,610
	Partners’ capital attributable to noncontrolling interests	69,929				159,961
	Noncontrolling interest in consolidated subsidiaries retained by SemGroup	—				78,557
	Total liabilities and partners’ capital	$	945,228			$	897,247
	Certain summarized income statement information of Rose Rock for the years ended December 31, 2014, 2013, and 2012 is shown below (in thousands):
		Year Ended December 31, 2014				Year Ended December 31, 2013				Year Ended December 31, 2012
	Revenue	$	1,290,644			$	766,526			$	620,417
	Costs of products sold	$	1,131,362			$	663,759			$	546,966
	Operating, general and administrative expenses	$	97,575			$	51,082			$	35,385
	Depreciation and amortization expense	$	36,072			$	23,165			$	12,131
	Earnings from equity method investment	$	57,378			$	17,571			$	—
	Net income	$	62,577			$	38,005			$	23,954
	Noncontrolling interest in consolidated subsidiaries retained by SemGroup	$	7,758			$	1,256			$	—
	Net income attributable to Rose Rock Midstream, L.P.	$	54,819			$	36,749			$	23,954
	Drop-down Transactions with Rose Rock
	2014 drop-down transaction
	On June 23, 2014, we contributed the remaining 33% interest in SemCrude Pipeline, L.L.C. ("SCPL") to Rose Rock in exchange for (i) cash of approximately $114.4 million, (ii) the issuance of 2.425 million common units, (iii) the issuance of 1.25 million Class A units, and (iv) an increase of the capital account of the general partner and a related issuance of general partner interest, to allow the general partner to maintain its 2% general partner interest. Subsequent to this transaction, Rose Rock owns 100% of SCPL, which owns a 51% membership interest in White Cliffs.
	The Class A units were not entitled to receive any distribution of available cash (other than upon liquidation) prior to the first day of the month immediately following the first month for which the average daily throughput volumes on the White Cliffs Pipeline for such month are 125,000 barrels per day or greater. The Class A units converted to common units in January 2015.
	As this transaction was between parties under common control, Rose Rock recorded its interest in SCPL at SemGroup's historical value and as such no gain on the sale was recognized by SemGroup. Proceeds in excess of the historical value were accounted for as a dividend from Rose Rock to SemGroup and resulted in a $85.2 million reduction to noncontrolling interests in consolidated subsidiaries and an offsetting increase to additional paid-in capital of $53.2 million (net of tax impact of $31.9 million). This non-cash entry represents the portion of the proceeds in excess of historical cost which were attributed to Rose Rock's third-party unitholders. SemGroup used the proceeds from these transactions to pay amounts owed under its revolving credit facility.
SemGroup incurred approximately $0.9 million of expense associated with this transaction, including $0.4 million of costs incurred by Rose Rock.
2013 drop-down transactions
On January 11, 2013, we contributed a 33% interest in SCPL to Rose Rock in exchange for (i) cash of approximately $189.5 million, (ii) the issuance of 1.5 million common units, (iii) the issuance of 1.25 million Class A units and (iv) an increase of the capital account of the general partner of Rose Rock and a related issuance of general partner interest, to allow the general partner of Rose Rock to maintain its 2% general partner interest.
In connection with this transaction, Rose Rock issued and sold 2.0 million common units to third-party purchasers in a private placement for aggregate consideration of approximately $59.3 million. In addition, Rose Rock made a borrowing of $133.5 million under its revolving credit facility. The proceeds from the private placement and the borrowing were used by Rose Rock to fund the cash consideration in the transaction with us and to pay certain related transaction costs and expenses.
On December 16, 2013, we contributed an additional 33% interest in SCPL to Rose Rock in exchange for (i) cash of approximately $173.1 million, (ii) the issuance of 1.5 million common units, (iii) the issuance of 1.25 million Class A units, and (iv) an increase of the capital account of the general partner of Rose Rock and a related issuance of general partner interest, to allow the general partner of Rose Rock to maintain its 2% general partner interest. The cash consideration was funded through a borrowing under Rose Rock's credit facility.
As these transactions were between parties under common control, Rose Rock recorded its interest in SCPL at SemGroup's historical value and as such no gain was recognized by SemGroup. Proceeds in excess of the historical value were accounted for as a dividend from Rose Rock to SemGroup and resulted in a $180.2 million reduction to noncontrolling interests in consolidated subsidiaries and an offsetting increase to additional paid-in capital of $112.9 million (net of tax impact of $67.3 million). This non-cash entry represents the portion of the proceeds in excess of historical cost which were attributed to Rose Rock's third-party unitholders. SemGroup used the proceeds from these transactions to pay amounts owed under its revolving credit facility.
SemGroup incurred approximately $2.2 million of expense associated with these transactions, including expenses of Rose Rock. Rose Rock incurred $1.6 million of equity issuance costs which were offset against proceeds, $1.6 million of costs related to the January 2013 borrowing which were deferred, and $0.9 million of acquisition related costs which were expensed.
Rose Rock equity issuance
In August 2013, Rose Rock sold 4.75 million common limited partner units to third-party purchasers for $152.5 million, net of underwriting discounts and commissions. Proceeds were used to repay borrowings on the Rose Rock credit facility.
Rose Rock subsequent events
On January 1, 2015, certain operational targets were achieved by White Cliffs and all 3,750,000 Class A units held by the Company were converted to common units on a one-for-one basis. The conversion did not impact the total number of the Rose Rock's outstanding units representing limited partner interests.
On February 13, 2015, we contributed the Wattenberg Oil Trunkline and Glass Mountain Holding, LLC, which holds our 50% interest in Glass Mountain, to Rose Rock in exchange for (i) cash of approximately $251.2 million, (ii) the issuance of 1.75 million common units and (iii) an increase of the capital account of the general partner of Rose Rock and a related issuance of general partner interest, to allow the general partner of Rose Rock to maintain its 2% general partner interest. The cash consideration was funded through a borrowing under Rose Rock's credit facility and the issuance and sale of 2.3 million common units in an underwritten public offering for net proceeds of $89.1 million. As the acquisition was between parties under common control, Rose Rock will record its interest in acquired assets and liabilities at SemGroup's historical value and SemGroup will not recognize a gain on the transaction. Proceeds in excess of the historical value will be accounted for as a dividend from Rose Rock to SemGroup.
On February 17, 2015, certain targets specified in Rose Rock’s partnership agreement were achieved and all 8,389,709 subordinated units held by the Company were converted to common units. The conversion did not impact the total number of Rose Rock’s outstanding units representing limited partner interests.

Equity_Method_Investments

Equity Method Investments	12 Months Ended
	Dec. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	EQUITY METHOD INVESTMENTS
	Our equity method investments consist of the following (in thousands):
		December 31, 2014		December 31, 2013
	White Cliffs	$	269,635	$	224,095
	NGL Energy	162,246		208,848
	Glass Mountain	146,039		132,181
	Total equity method investments	$	577,920	$	565,124
	Our earnings from equity method investments consist of the following (in thousands):
		Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012
	White Cliffs	$	57,378	$	45,459		$	36,439
	NGL Energy*	2,343		7,123			(403		)
	Glass Mountain	4,478		(105		)	—
	Total earnings from equity method investments	$	64,199	$	52,477		$	36,036
	* Excluding gains on issuance of common units of $29.0 million and $26.9 million for the years ended December 31, 2014 and 2013, respectively.
	Cash distributions received from equity method investments consist of the following (in thousands):
		Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012
	White Cliffs	$	66,768	$	57,576		$	44,514
	NGL Energy	23,404		18,321			9,217
	Glass Mountain	6,823		—			—
	Total cash distributions received from equity method investments	$	96,995	$	75,897		$	53,731
	White Cliffs
	Certain summarized balance sheet information of White Cliffs is shown below (in thousands):
		December 31,		December 31,
		2014		2013
	Current assets	$	35,623	$	98,457
	Property, plant and equipment, net	471,179		312,831
	Goodwill	17,000		17,000
	Other intangible assets, net	16,043		20,802
	Total assets	$	539,845	$	449,090
	Current liabilities	$	11,108	$	9,648
	Members’ equity	528,737		439,442
	Total liabilities and members’ equity	$	539,845	$	449,090
	Certain summarized income statement information of White Cliffs for the years ended December 31, 2014, 2013 and 2012 is shown below (in thousands):
		Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012
	Revenue	$	160,369	$	133,310		$	108,125
	Operating, general and administrative expenses	$	23,067	$	23,825		$	14,821
	Depreciation and amortization expense	$	23,257	$	18,668		$	19,963
	Net income	$	114,045	$	90,817		$	73,341
	The equity in earnings of White Cliffs for the years ended December 31, 2014, 2013 and 2012 reported in our consolidated statements of operations is less than 51% of the net income of White Cliffs for the same period. This is due to certain general and administrative expenses we incur in managing the operations of White Cliffs that the other members are not obligated to share. Such expenses are recorded by White Cliffs, and are allocated to our membership interests. White Cliffs recorded $1.6 million, $1.8 million and $2.0 million of such general and administrative expense for the years ended December 31, 2014, 2013 and 2012, respectively.
	The members of White Cliffs are required to fund capital contribution requirements for White Cliffs related to an expansion project adding approximately 65,000 barrels per day of capacity. We expect to contribute $40.0 million for this project. The project is expected to be complete in late 2015.
	In August 2014, White Cliffs completed an expansion project adding a parallel 12" pipeline from Platteville, Colorado to Cushing, Oklahoma. For the years ended December 31, 2014, 2013 and 2012, we contributed $53.3 million, $95.5 million and $2.3 million, respectively, for project funding. This expansion increased White Cliffs’ capacity to about 150,000 barrels per day and became fully operational in the third quarter of 2014.
	Our membership interest in White Cliffs is significant as defined by Securities and Exchange Commission’s Regulation S-X Rule 1-02(w). Accordingly, as required by Regulation S-X Rule 3-09, we have included the audited financial statements of White Cliffs as of December 31, 2014 and 2013 and for each of the three years in the period ended December 31, 2014 as an exhibit to this Form 10-K.
	NGL Energy
	At December 31, 2014, we owned 6,652,101 common units representing limited partner interests in NGL Energy, which represents approximately 7.5% of the limited partner units of NGL Energy outstanding at September 30, 2014, and an 11.78% interest in the general partner of NGL Energy.
	On October 27, 2014, we agreed to terminate our right to appoint two representatives to the Board of Directors of NGL Energy Holdings LLC, the general partner of NGL Energy, and our current representatives resigned. We no longer have significant influence over NGL Energy Holdings, LLC or NGL Energy. However, in accordance with ASC 323-30-S99-1, we have continued to account for these investments under the equity method as our ownership is above the 3 to 5 percent interest which is generally considered to be more than minor.
	At December 31, 2014, the fair market value of our 6,652,101 common unit investment in NGL Energy was $186.2 million, based on a December 31, 2014 closing price of $27.99 per common unit. This does not reflect our 11.78% interest in the general partner of NGL Energy. The fair value of our limited partner investment in NGL Energy is categorized as a Level 1 measurement, as it is based on quoted market prices.
	Our policy is to record our equity in earnings of NGL Energy on a one-quarter lag, as we do not expect information on the earnings of NGL Energy to always be available in time to consistently record the earnings in the quarter in which they are generated. Accordingly, the equity in earnings from NGL Energy, which is reflected in our consolidated statements of operations and comprehensive income for the years ended December 31, 2014, 2013 and 2012 relates to the earnings of NGL Energy for the twelve months ended September 30, 2014, 2013 and 2012 respectively.
	Certain unaudited summarized balance sheet information of NGL Energy is shown below (in thousands):
		(unaudited)		(unaudited)
		September 30,		September 30,
		2014		2013
	Current assets	$	2,585,053	$	1,013,859
	Property plant and equipment, net	1,433,313		631,663
	Goodwill	1,170,490		840,287
	Intangible and other assets, net	1,362,823		540,684
	Total assets	$	6,551,679	$	3,026,493
	Current liabilities	$	1,759,980	$	800,658
	Long-term debt	2,437,351		906,066
	Other noncurrent liabilities	39,518		2,673
	Equity	2,314,830		1,317,096
	Total liabilities and equity	$	6,551,679	$	3,026,493
	Certain unaudited summarized income statement information of NGL Energy for the twelve months ended September 30, 2014 and 2013 is shown below (in thousands):
		(unaudited)		(unaudited)			(unaudited)
		Twelve Months Ended		Twelve Months			Twelve Months
September 30,		Ended			Ended
2014		September 30,			September 30,
		2013			2012
Revenue	$	15,748,520	$	5,935,715		$	2,371,524
Costs of products sold	$	15,054,291	$	5,478,361		$	2,182,263
Operating, general and administrative expenses	$	440,609	$	276,905		$	125,889
Depreciation and amortization expense	$	162,443	$	94,050		$	34,621
Net income	$	11,409	$	44,378		$	5,405
Our limited partnership interest was diluted in connection with NGL Energy equity offerings and equity issued as consideration for acquisitions in 2014 and 2013. Accordingly, we recorded non-cash gains of $29.0 million and $26.9 million for the years ended December 31, 2014 and 2013, respectively, related to these transactions, which are included in "gain on issuance of common units by equity method investee" in our consolidated statements of operations and comprehensive income.
During the year ended December 31, 2014, we sold 2,481,308 of our NGL Energy common units for $88.8 million, net of related costs of $3.1 million. We recorded a net gain of approximately $34.2 million in "other expense (income), net" in our consolidated statement of operations and comprehensive income.
Subsequent to December 31, 2014, we sold 999,533 of our NGL Energy common units for $29.0 million, net of related costs of $0.4 million. We realized a net gain of approximately $7.5 million as a result of these transactions.
Our ownership interest in NGL Energy is significant as defined by Securities and Exchange Commission’s Regulation S-X Rule 1-02(w). Accordingly, as required by Regulation S-X Rule 3-09, we will amend this Form 10-K to include the audited financial statements of NGL Energy as of March 31, 2015 and 2014 and for each of the three years in the period ended March 31, 2015 as an exhibit, when available.
Glass Mountain
We hold a 50% interest in Glass Mountain which we account for under the equity method. Glass Mountain began operations in the first quarter of 2014. We invested $16.2 million and $57.8 million in Glass Mountain for the years ended December 31, 2014 and 2013, respectively, including our capital contributions, amounts paid to acquire additional ownership interests, and capitalized interest.
The excess of the recorded amount of our investment over the book value of our share of the underlying net assets represents equity method goodwill and capitalized interest of $31.0 million and $4.1 million, respectively, at December 31, 2014. Capitalized interest is amortized as a reduction of earnings from equity method investments.
The equity in earnings of Glass Mountain for the year ended December 31, 2014 reported in our consolidated statement of operations and comprehensive income is less than 50% of the net income of Glass Mountain for the same period due to amortization of capitalized interest for the period.
Certain summarized balance sheet information of Glass Mountain is shown below (in thousands):
	December 31,
	2014
Current assets	$	8,810
Property, plant and equipment, net	215,876
Total assets	$	224,686
Current liabilities	$	2,643
Other Liabilities	42
Members’ equity	222,001
Total liabilities and members’ equity	$	224,686
Certain unaudited summarized income statement information of Glass Mountain for the year ended December 31, 2014 is shown below (in thousands):
	Year Ended December 31, 2014
Revenue	$	30,398
Operating, general and administrative expenses	$	7,176
Depreciation and amortization expense	$	13,872
Net income	$	9,344
Our ownership interest in Glass Mountain is not significant as defined by Securities and Exchange Commission's Regulation S-X Rule 1-02(w). Accordingly, no audited financial statements of Glass Mountain pursuant to Regulation S-X 3-09 have been included as an exhibit to this Form 10-K.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2014
Acquisitions [Abstract]
Business Combination Disclosure [Text Block]	ACQUISITIONS
	Crude oil trucking assets
	On June 24, 2014, our consolidated subsidiary, Rose Rock, acquired crude oil trucking assets from a subsidiary of Chesapeake Energy Corporation ("Chesapeake") (NYSE: CHK) for $44.0 million in cash. Highlights of the transaction include:
	•	124 trucks, 122 trailers and miscellaneous equipment; and
	•	a long-term transportation agreement with Chesapeake Energy Marketing, Inc.
	The results of operations of these assets from June 24, 2014 through December 31, 2014 have been included in our Crude segment in our consolidated statements of operations and comprehensive income and balance sheet as of December 31, 2014. During the year ended December 31, 2014, our consolidated statements of operation and comprehensive income did not include material amounts of revenue or operating income related to these assets. The proforma impact to comparative prior year periods, had the acquisition occurred at the beginning of the comparative prior year period, is not significant.
	Fair values of the acquired assets were determined based on the cost, income and market approach methodologies. The trucks and equipment acquired were valued based on the cost approach, which considers the replacement cost of the assets adjusted for depreciation and physical deterioration, and the market approach, which considers the value of transactions for comparable assets. The value of the customer contract was determined based on the income approach using the excess earnings method over the remaining life of the contract and assuming a 95% probability of renewal.
	We have recorded the fair value of the assets acquired as follows (in thousands):
	Property, plant and equipment	$	19,092
	Customer contract intangible	17,010
	Goodwill	7,892
	Total assets acquired	$	43,994
	The above finalized purchase price allocation resulted in adjustments to previously reported estimates. Our preliminary estimate of the value of the acquired property, plant and equipment was reduced by $2.6 million and our estimate of the value of the intangible asset was increased by $12.6 million which resulted in a decrease in the value of the associated goodwill of $10.0 million.
	Goodwill represents the excess of the estimated consideration paid for the acquired business over the fair value of the individual assets acquired. Goodwill primarily represents the value of the acquired business as a platform for growth and the acquired assembled workforce.
	Mid-America Midstream Gas Services, L.L.C.
	On August 1, 2013, our SemGas segment acquired the equity interest of Mid-America Midstream Gas Services, L.L.C. ("MMGS"), a wholly owned subsidiary of Chesapeake, which is the owner of gas gathering and processing assets in the Mississippi Lime play for approximately $314.0 million in cash. We incurred approximately $3.6 million in transaction related general and administrative expenses. The transaction was funded through the combination of a portion of the net proceeds from the sale of $300 million of 7.50% senior unsecured notes (Note 16) and a borrowing under the revolving credit facility under SemGroup's corporate credit agreement. Highlights of the acquisition include the following:
	•	200 miles of gathering pipeline;
	•	Rose Valley I plant - A 200 mmcf/d (million cubic feet per day) cryogenic processing plant, placed in operation in the first quarter of 2014;
	•	Rose Valley II plant - A 200 mmcf/d cryogenic processing plant, expected to be in operation in mid-2015;
	•	Approximately 540,000 net acre dedication in the core of the Mississippi Lime play, supported by a joint venture between Chesapeake and Sinopec International Petroleum Exploration and Production Corporation ("Sinopec"); and
	•	A 20-year, 100% fee based, gas gathering and processing agreement with certain affiliates of Chesapeake and Sinopec.
	Fair values of the acquired assets were determined based on the cost, income and market approach methodologies. The property, plant and equipment acquired were valued based on the cost approach, which considers the replacement cost of the assets adjusted for depreciation and physical deterioration, and the market approach, which considers the value of transactions for comparable assets. The value of the customer contract was determined based on the income approach using the excess earnings method over the remaining life of the contract and assuming no renewal.
	We have recorded the fair value of the assets acquired as follows (in thousands):
	Property, plant and equipment	$	136,949
	Customer contract intangible	164,000
	Goodwill	13,052
	Total assets acquired	$	314,001
	Based on the final purchase price allocation, the amounts above were adjusted from those reported at December 31, 2013 by a non-cash adjustment which decreased goodwill and customer contract intangible by $10.8 million and $2.3 million, respectively, with a corresponding increase to property, plant and equipment. In addition, we recorded $0.5 million of incremental payments for property, plant and equipment, which related to the period prior to close of the transaction.
	Goodwill represents the excess of the estimated consideration paid for the acquired business over the fair value of the individual assets acquired. Goodwill primarily represents the value of operational efficiencies between the acquired entity and the Company's existing assets in the area and the opportunity to use the acquired business as a platform for growth.
	Barcas Field Services, LLC
	On September 1, 2013, our consolidated subsidiary, Rose Rock, completed the acquisition of the assets of Barcas Field Services, LLC ("Barcas") for $49.0 million in cash. Highlights of the acquisition include the following:
	•	114 trucks, 120 trailers and miscellaneous equipment; and
	•	a long-term take-or-pay customer transportation agreement.
	Fair values of the acquired assets were determined based on the cost, income and market approach methodologies. The trucks and equipment acquired were valued based on the cost approach which considers the replacement cost of the assets adjusted for depreciation and physical deterioration. The value of the customer contract was determined based on the income approach using the excess earnings method over the remaining life of the contract and assuming a 50% probability of renewal. The market approach which considers the value of comparable transactions was used to value the acquired land.
	We have recorded the following acquisition date fair values for the assets acquired (in thousands):
	Property, plant and equipment	$	13,865
	Customer contract intangible	6,880
	Goodwill	28,234
	Total assets acquired	$	48,979
	Based on the final purchase price allocation, the amounts above differ from those reported at December 31, 2013 by a non-cash adjustment which decreased goodwill and other intangible assets and increased property, plant and equipment by $0.1 million.
	Goodwill represents the excess of the consideration paid for the acquired business over the fair value of the individual assets acquired. Goodwill primarily represents cost savings due to the ability to transport using the acquired trucks rather than third-party trucks, the ability to bring more volume from the field into our pipelines, the opportunity to use the acquired business as a platform for growth and the acquired assembled workforce.
	NGL Energy
	On August 6, 2013, we completed the acquisition of approximately 5.36% of the general partner of NGL Energy, which increased our ownership of NGL Energy's general partner to 11.78%.
	Glass Mountain
	In September 2012, we acquired an additional 25% ownership interest in Glass Mountain, bringing our total ownership percentage in Glass Mountain to 50%. See Note 5 for additional information related to our equity method investment in Glass Mountain.

Disposals_of_LongLived_Assets

Disposals of Long-Lived Assets	12 Months Ended
	Dec. 31, 2014
Disposals And Impairments Of Long-Lived Assets [Abstract]
Disposals of Long-Lived Assets	DISPOSALS OR IMPAIRMENTS OF LONG-LIVED ASSETS
	Year Ended December 31, 2014
	On June 1, 2014, our SemGas segment sold certain natural gas gathering assets in Eastern Oklahoma resulting in a $20.1 million pre-tax loss on a cash sales price of $2.4 million. The assets sold were made up of property, plant and equipment with a net book value of $22.5 million. The loss on the sale was reported in "loss (gain) on disposal or impairment of long-lived assets, net" in the consolidated statement of operations and comprehensive income. The operations of the gas gathering assets were not material to SemGroup.
	During the year ended December 31, 2014, we recorded an impairment charge of $11.9 million related to leaseholds of unproved oil and gas properties located in Kansas. These assets were written off when due to the downturn in crude oil prices and the remaining life of the leaseholds, it became apparent that these properties would not be developed. These assets were held by a subsidiary included in Corporate and Other in our segment disclosures (Note 9).
	Year Ended December 31, 2013
	There were no significant gains (losses) recorded during the year ended December 31, 2013 related to the disposal of long-lived assets.
	Year Ended December 31, 2012
	Gains (losses) recorded during the year ended December 31, 2012 related to the disposal of long-lived assets including the following (in thousands):
	Event	Segment	Pre-Tax Gain
	White Cliffs settlement (a)	Crude	$	3,500
	Sale of SemStream residential division assets and liabilities (b)	SemStream	$	3,090
	(a)	We sold a portion of our ownership interest in White Cliffs during September 2010. At the time, we recorded a loss of $6.8 million on disposal of that asset. In September 2012, we reached a settlement in a dispute concerning the selling price of that ownership interest and reduced the loss by $3.5 million. This $3.5 million gain is reported in "gain on disposal or impairment of long-lived assets, net" in the consolidated statements of operations and comprehensive income.
	(b)	On September 12, 2012, we entered into a definitive agreement to sell the assets and liabilities of SemStream’s Arizona residential business which was subject to regulatory approval by the Arizona Corporation Commission (the "ACC"). In early December 2012, the ACC granted SemStream regulatory approval to proceed with the sale. The sale closed on December 31, 2012 and resulted in a gain of $3.1 million on a cash sales price of $12.3 million. The $3.1 million gain is reported in "income (loss) from discontinued operations, net of income taxes" in the consolidated statements of operations and comprehensive income. Property, plant, and equipment with a carrying value of $9.4 million represented the majority of assets included in the sale.

Discontinued_Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	DISCONTINUED OPERATIONS
	On December 31, 2012, we completed the sale of SemStream's Arizona residential business which was classified as a discontinued operation. The sale resulted in a gain of $3.1 million. There continues to be an insignificant amount of activity related to ongoing bankruptcy matters which is reflected in the results below and is related to operations discontinued during bankruptcy.
	Certain summarized information on the results of discontinued operations is shown below (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013		Year Ended December 31, 2012
	External revenue	$	—		$	—	$	13,518
	Gain on disposal of long-lived assets, net	$	—		$	—	$	3,090
	Income (loss) from discontinued operations before income taxes	$	(1	)	$	59	$	2,935
	Income tax benefit	—			—		(4		)
	Income (loss) from discontinued operations, net of income taxes	$	(1	)	$	59	$	2,939

Segments

Segments	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segments	SEGMENTS
	As described in Note 1, our businesses are organized based on the nature and location of the services they provide. Certain summarized information related to our reportable segments is shown in the tables below. None of the operating segments have been aggregated, other than Rose Rock and Glass Mountain, which have been included within the Crude segment and were aggregated based on similarity of operations, customer base and other considerations. Our equity investment NGL Energy is included within the SemStream segment. Although Corporate and Other does not represent an operating segment, it is included in the tables below to reconcile segment information to that of the consolidated Company. Eliminations of transactions between segments are also included within Corporate and Other in the tables below.
	The accounting policies of each segment are the same as the accounting policies of the consolidated Company. Transactions between segments are generally recorded based on prices negotiated between the segments. Certain general and administrative and interest expenses incurred at the corporate level were allocated to the segments, based on our allocation policies in effect at the time.
		Year Ended December 31, 2014
		Crude			SemStream			SemCAMS			SemGas			SemLogistics			SemMexico			Corporate			Consolidated
																				and
																				Other
		(in thousands)
	Revenues:
	External	$	1,300,050		$	—		$	176,724		$	342,286		$	12,650		$	290,869		$	—		$	2,122,579
	Intersegment	—			—			—			37,897			—			—			(37,897		)	—
	Total revenues	1,300,050			—			176,724			380,183			12,650			290,869			(37,897		)	2,122,579
	Expenses:
	Costs of products sold, exclusive of depreciation and amortization shown below	1,131,362			—			344			276,852			615			252,082			(37,897		)	1,623,358
	Operating	80,793			—			114,587			32,296			8,361			10,576			—			246,613
	General and administrative	20,351			83			17,417			9,228			6,139			12,125			22,502			87,845
	Depreciation and amortization	40,035			—			14,295			26,353			10,005			6,031			1,678			98,397
	Loss (gain) on disposal or impairment of long-lived assets, net	319			—			(950		)	20,092			(2,490		)	(53		)	15,674			32,592
	Total expenses	1,272,860			83			145,693			364,821			22,630			280,761			1,957			2,088,805
	Earnings from equity method investments	61,856			2,343			—			—			—			—			—			64,199
	Gain on issuance of common units by equity method investee	—			29,020			—			—			—			—			—			29,020
	Operating income (loss)	89,046			31,280			31,031			15,362			(9,980		)	10,108			(39,854		)	126,993
	Other expenses (income), net
	Interest expense (income)	31,072			(5,140		)	13,558			8,570			1,528			166			(710		)	49,044
	Other expense (income), net	479			(34,212		)	20			—			796			(11		)	12,306			(20,622		)
	Total other expenses (income)	31,551			(39,352		)	13,578			8,570			2,324			155			11,596			28,422
	Income (loss) from continuing operations before income taxes	$	57,495		$	70,632		$	17,453		$	6,792		$	(12,304	)	$	9,953		$	(51,450	)	$	98,571
	Additions to long-lived assets	$	127,335		$	—		$	35,286		$	166,207		$	2,974		$	9,690		$	1,672		$	343,164
	Total assets at December 31, 2014 (excluding intersegment receivables)	$	1,158,639		$	162,246		$	279,191		$	662,223		$	150,498		$	107,225		$	69,780		$	2,589,802
	Equity investments at December 31, 2014	$	415,674		$	162,246		$	—		$	—		$	—		$	—		$	—		$	577,920
		Year Ended December 31, 2013
		Crude			SemStream			SemCAMS			SemGas			SemLogistics			SemMexico			Corporate			Consolidated
																				and
																				Other
		(in thousands)
	Revenues:
	External	$	767,202		$	—		$	198,450		$	207,134		$	11,671		$	242,559		$	—		$	1,427,016
	Intersegment	—			—			—			23,985			—			—			(23,985		)	—
	Total revenues	767,202			—			198,450			231,119			11,671			242,559			(23,985		)	1,427,016
	Expenses:
	Costs of products sold, exclusive of depreciation and amortization shown below	663,759			—			305			169,800			380			209,841			(23,985		)	1,020,100
	Operating	36,242			1			150,319			20,200			7,444			9,379			—			223,585
	General and administrative	16,766			600			14,940			7,971			5,854			10,700			21,766			78,597
	Depreciation and amortization	23,708			—			10,766			14,517			9,426			5,991			2,001			66,409
	Loss (gain) on disposal of long-lived assets, net	(56		)	6			—			665			—			(854		)	—			(239		)
	Total expenses	740,419			607			176,330			213,153			23,104			235,057			(218		)	1,388,452
	Earnings from equity method investments	45,354			7,123			—			—			—			—			—			52,477
	Gain on issuance of common units by equity method investee	—			26,873			—			—			—			—			—			26,873
	Operating income (loss)	72,137			33,389			22,120			17,966			(11,433		)	7,502			(23,767		)	117,914
	Other expenses (income), net
	Interest expense (income)	14,923			(4,810		)	18,928			3,268			1,435			188			(8,790		)	25,142
	Other expense (income), net	(14		)	128			(20		)	(3		)	(400		)	(652		)	45,234			44,273
	Total other expenses (income)	14,909			(4,682		)	18,908			3,265			1,035			(464		)	36,444			69,415
	Income (loss) from continuing operations before income taxes	$	57,228		$	38,071		$	3,212		$	14,701		$	(12,468	)	$	7,966		$	(60,211	)	$	48,499
	Additions to long-lived assets	$	66,995		$	—		$	56,122		$	97,021		$	2,071		$	6,375		$	734		$	229,318
	Total assets at December 31, 2013 (excluding intersegment receivables)	$	1,070,484		$	208,847		$	306,001		$	552,095		$	168,835		$	104,154		$	60,198		$	2,470,614
	Equity investments at December 31, 2013	$	356,276		$	208,848		$	—		$	—		$	—		$	—		$	—		$	565,124
		Year Ended December 31, 2012
		Crude			SemStream			SemCAMS			SemGas			SemLogistics			SemMexico			Corporate			Consolidated
																				and
																				Other
		(in thousands)
	Revenues:
	External	$	620,797		$	7		$	223,219		$	117,264		$	12,341		$	263,870		$	(1	)	$	1,237,497
Intersegment	—			—			—			10,606			—			—			(10,606		)	—
Total revenues	620,797			7			223,219			127,870			12,341			263,870			(10,607		)	1,237,497
Expenses:
Costs of products sold, exclusive of depreciation and amortization shown below	546,966			33			768			100,677			196			236,851			(10,606		)	874,885
Operating	24,143			(37		)	174,284			12,712			5,921			7,677			—			224,700
General and administrative	13,321			930			14,020			6,195			5,652			9,433			22,367			71,918
Depreciation and amortization	12,131			—			10,589			7,043			9,780			6,171			2,496			48,210
Loss (gain) on disposal of long-lived assets, net	(3,501		)	214			—			46			—			(290		)	—			(3,531		)
Total expenses	593,060			1,140			199,661			126,673			21,549			259,842			14,257			1,216,182
Earnings from equity method investments	36,439			(403		)	—			—			—			—			—			36,036
Operating income (loss)	64,176			(1,536		)	23,558			1,197			(9,208		)	4,028			(24,864		)	57,351
Other expenses (income):
Interest expense (income)	(409		)	(3,449		)	18,727			1,461			2,486			314			(10,228		)	8,902
Other expense (income), net	31			(21		)	14			—			(420		)	(38		)	22,003			21,569
Total other expenses	(378		)	(3,470		)	18,741			1,461			2,066			276			11,775			30,471
Income (loss) from continuing operations before income taxes	$	64,554		$	1,934		$	4,817		$	(264	)	$	(11,274	)	$	3,752		$	(36,639	)	$	26,880
Additions to long-lived assets	$	41,364		$	—		$	13,340		$	47,140		$	1,188		$	3,396		$	14,827		$	121,255
Income tax expense (benefit) relates to the following segments (in thousands):
	Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
SemCAMS	$	3,135		$	6,348		$	720
SemLogistics	(2,231		)	(5,699		)	(7,736		)
SemMexico	4,053			2,589			2,285
Corporate and other	41,556			(20,492		)	2,653
Total	$	46,513		$	(17,254	)	$	(2,078	)

Inventories

Inventories	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories	INVENTORIES
	Inventories consist of the following (in thousands):
		December 31,		December 31,
		2014		2013
	Crude oil	$	26,722	$	30,779
	Asphalt and other	16,810		13,516
	Total inventories	$	43,532	$	44,295
	During the year ended December 31, 2014, our Crude segment recorded non-cash charges of $5.7 million to write-down crude oil inventory to the lower of cost or market.

Other_Assets

Other Assets	12 Months Ended
	Dec. 31, 2014
Other Assets [Abstract]
Other Assets
		OTHER ASSETS
	Other current assets consist of the following (in thousands):
		December 31,			December 31,
		2014			2013
	Prepaid expenses	$	5,989		$	5,696
	Deferred tax asset	5,897			7,325
	Other	8,131			990
	Total other current assets	$	20,017		$	14,011
	Other noncurrent assets consist of the following (in thousands):
		December 31,			December 31,
		2014			2013
	Debt issuance costs, net	$	22,203	*	$	17,149	*
	Deferred tax asset	13,933			2,832
	Other	8,250			8,908
	Total other noncurrent assets, net	$	44,386		$	28,889
	* See Note 16 for discussion of debt issuance costs.

Property_Plant_and_Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment
		PROPERTY, PLANT AND EQUIPMENT
	Property, plant and equipment consists of the following (in thousands):
		December 31,			December 31,
		2014			2013
	Land	$	81,886		$	72,484
	Pipelines and related facilities	283,347			312,730
	Storage and terminal facilities	284,300			281,819
	Natural gas gathering and processing facilities	606,553			347,962
	Linefill	26,050			14,701
	Trucking equipment and other	40,392			31,978
	Office property and equipment	37,120			33,701
	Construction-in-progress	142,806			199,073
	Property, plant and equipment, gross	1,502,454			1,294,448
	Accumulated depreciation	(245,629		)	(188,720		)
	Property, plant and equipment, net	$	1,256,825		$	1,105,728
	We recorded depreciation expense of $82.5 million, $60.4 million and $46.2 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	We include within the cost of property, plant and equipment interest costs incurred while an asset is being constructed. We capitalized $1.5 million and $4.3 million of interest costs during the years ended December 31, 2014 and 2013, respectively.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill And Other Intangible Assets [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS
	Goodwill
	Goodwill relates to the following segments (in thousands):
		December 31,			December 31,
		2014			2013
	Crude	$	36,116		$	28,322
	SemGas	13,052			23,839
	SemMexico	9,158			9,860
	Total Goodwill	$	58,326		$	62,021
	In addition to the amounts in the table above, approximately $71.4 million of our investment in NGL Energy and $31.0 million of our investment in Glass Mountain represents equity method goodwill. Equity method goodwill is not amortized and is tested for impairment with the equity method investment in accordance with ASC 323.
	We assess our goodwill for impairment at least annually as of October 1. Our goodwill impairment analysis performed as of October 1, 2014, did not result in an impairment charge nor did our analysis reflect any reporting units at risk, and subsequent to that date, no event has occurred indicating that the implied fair value of each of our reporting units (including its inherent goodwill) is less than the carrying value of its net assets.
	Changes in goodwill balances during the period from December 31, 2011 to December 31, 2014 are shown below (in thousands):
	Balance, December 31, 2011	$	9,453
	Currency translation adjustments	431
	Balance, December 31, 2012	9,884
	Barcas acquisition (Note 6)	28,322
	MMGS acquisition (Note 6)	23,839
	Currency translation adjustments	(24		)
	Balance, December 31, 2013	62,021
	Crude oil trucking asset acquisition (Note 6)	7,892
	MMGS purchase price allocation adjustment (Note 6)	(10,787		)
	Barcas purchase price allocation adjustment (Note 6)	(98		)
	Currency translation adjustments	(702		)
	Balance, December 31, 2014	$	58,326
	For U.S. federal income tax purposes, goodwill is amortized on a straight-line basis over 15 years.
	Other intangible assets
	Other intangible assets relate to the following segments (in thousands):
		December 31,			December 31,
		2014			2013
	Crude	$	16,640		$	5,775
	SemGas	152,383			163,144
	SemMexico	4,016			5,888
	Corporate and other	26			31
	Total other intangible assets	$	173,065		$	174,838
	Changes in other intangible asset balances are shown below (in thousands):
	Balance, December 31, 2011	$	8,950
	Amortization	(2,017		)
	Currency translation adjustments	652
	Balance, December 31, 2012	7,585
	Amortization	(6,018		)
	Barcas acquisition (Note 6)	6,930
	MMGS acquisition (Note 6)	166,332
	Currency translation adjustments	9
	Balance, December 31, 2013	174,838
	Amortization	(15,875		)
	Crude oil trucking asset acquisition (Note 6)	17,010
	MMGS purchase price allocation adjustment (Note 6)	(2,313		)
	Barcas purchase price allocation adjustment (Note 6)	(50		)
	Currency translation adjustments	(545		)
	Balance, December 31, 2014	$	173,065
	Our other intangible assets consist primarily of customer relationships at our Crude, SemGas and SemMexico segments and unpatented technology of our SemMexico segment, which represented $171.6 million and $1.3 million, respectively, of the balance at December 31, 2014. These assets may be subject to impairments in the future if we are unable to maintain the relationships with the customers to which the assets relate.
	For the year ended December 31, 2014, we recorded a $17.0 million customer contract intangible asset related to the crude oil trucking asset acquisition. The intangible is being amortized in proportion with the expected revenues associated with the contract over 20 years.
	We estimate that future amortization of other intangible assets will be as follows (in thousands):
	For year ending:
	31-Dec-15	$	10,334
	31-Dec-16	10,928
	31-Dec-17	11,011
	31-Dec-18	10,918
	31-Dec-19	10,317
	Thereafter	119,557
	Total estimated amortization expense	$	173,065

Financial_Instruments_and_Conc

Financial Instruments and Concentrations of Risk	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Financial Instruments and Concentrations of Risk	FINANCIAL INSTRUMENTS AND CONCENTRATIONS OF RISK
	Fair value of financial instruments
	We record certain financial assets and liabilities at fair value at each balance sheet date. The tables below summarize the balances of commodity derivative assets and liabilities at December 31, 2014 and 2013 (in thousands):
		December 31, 2014										December 31, 2013
	Derivatives subject to netting arrangements:	Level 1			Netting*				Total			Level 1		Netting*			Total
	Commodity derivatives:
	Assets	$	3,311		$	(1,637	)		$	1,674		$	36	$	(36	)	$	—
	Liabilities	$	1,637		$	(1,637	)		$	—		$	96	$	(36	)	$	60
	*	Relates primarily to exchange traded futures. Gain and loss positions on multiple contracts are settled net on a daily basis with the exchange.
	“Level 1” measurements are based on inputs consisting of unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. These include commodity futures contracts that are traded on an exchange. The valuation of our common stock warrants which were traded on the New York Stock Exchange was also classified as Level 1.
	“Level 2” measurements are based on inputs consisting of market observable and corroborated prices for similar commodity derivative contracts. Assets and liabilities classified as Level 2 include over-the-counter ("OTC") traded forwards contracts and swaps.
	“Level 3” measurements are obtained using information from a pricing service and internal valuation models incorporating observable and unobservable market data. These include commodity derivatives, such as forwards and swaps for which there is not a highly liquid market, and therefore are not included in Level 2 above.
	Financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the measurement requires judgment, and may affect the valuation of assets and liabilities and their placement within the fair value levels.
	There were no financial assets or liabilities classified as Level 2 or Level 3 during the years ended December 31, 2014, 2013 and 2012, as such no rollforward of activity has been presented.
	Commodity derivative contracts
	Our consolidated results of operations and cash flows are impacted by changes in market prices for petroleum products. This exposure to commodity price risk is managed, in part, by entering into various commodity derivatives.
	We seek to manage the price risk associated with our marketing operations by limiting our net open positions through (i) the concurrent purchase and sale of like quantities of petroleum products to create back-to-back transactions that are intended to lock in positive margins based on the timing, location or quality of the petroleum products purchased and delivered or (ii) derivative contracts. Our storage and transportation assets can also be used to mitigate location and time basis risk. All marketing activities are subject to our Comprehensive Risk Management Policy, which establishes limits in order to manage risk and mitigate financial exposure.
	Our commodity derivatives can be comprised of swaps, futures contracts and forward contracts of crude oil and natural gas liquids. These are defined as follows:
	Swaps – OTC transactions where a floating price, basis or index is exchanged for a fixed (or a different floating) price, basis or index at a preset schedule in the future, according to an agreed-upon formula.
	Futures contracts – Exchange traded contracts to buy or sell a commodity. These contracts are standardized by the exchange in terms of quality, quantity, delivery period and location for each commodity.
	Forward contracts – OTC contracts to buy or sell a commodity at an agreed upon future date. The buyer and seller agree on specific terms (price, quantity, delivery period and location) and conditions at the inception of the contract.
	The following table sets forth the notional quantities for derivative instruments entered into (in thousands of barrels):
		Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012
	Sales	6,773		2,595			1,743
	Purchases	6,477		2,575			1,636
	We have not designated any of our commodity derivative instruments as accounting hedges. We have recorded the fair value of our commodity derivative instruments on our consolidated balance sheets in "other current assets" and "other current liabilities" in the following amounts (in thousands):
	December 31, 2014							December 31, 2013
	Other Current Assets			Other Current Liabilities				Other Current Assets			Other Current Liabilities
	$	1,674		$	—			$	—		$	60
	We have posted margin deposits as collateral with brokers who have the right of set off associated with these funds. Our margin deposit balances were $0.8 million and $0.8 million at December 31, 2014 and 2013, respectively. These margin account balances have not been offset against our net commodity derivative instrument (contract) positions. Had these margin account balances been netted against our net commodity derivative instrument (contract) positions as of December 31, 2014 and 2013, we would have had net asset positions of $2.5 million and $0.8 million, respectively.
	Realized and unrealized gains (losses) from our commodity derivatives were recorded to product revenue in the following amounts (in thousands):
	Year Ended December 31, 2014			Year Ended December 31, 2013				Year Ended December 31, 2012
	$	19,305		$	(1,593	)		$	149
	Warrants
	In addition to the commodity derivatives above, we had $58.1 million of derivative liabilities related to common stock warrants at December 31, 2013, which are not subject to netting arrangements. The warrants were issued upon emergence from bankruptcy and were recorded at fair value on the consolidated balance sheets with changes in the fair value recorded to "other expense (income), net" in our consolidated statements of operations and comprehensive income. For the years ended December 31, 2014, 2013, and 2012, we recorded expense related to the change in fair value of $13.4 million, $46.4 million and $21.3 million, respectively. The warrants expired on November 30, 2014. See Note 18 for additional information.
	Concentrations of risk
	During the year ended December 31, 2014, one customer of our Crude segment accounted for more than 10% of our consolidated revenue at approximately 36%. We purchased approximately $469 million of product from one third-party supplier of our Crude segment, which represented approximately 29% of our costs of products sold. At December 31, 2014, two customers of our Crude segment accounted for approximately 34% of our consolidated accounts receivable.
	Assets and liabilities of subsidiaries outside the United States
	The following table summarizes the assets and liabilities (excluding affiliate balances) at December 31, 2014 of our subsidiaries outside the United States (in thousands):
		Canada			United				Mexico			Total
					Kingdom
	Cash and cash equivalents	$	17,710		$	957			$	13,253		$	31,920
	Other current assets	58,271			1,854				49,145			109,270
	Noncurrent assets	215,386			147,687				44,827			407,900
	Total assets	$	291,367		$	150,498			$	107,225		$	549,090
	Current liabilities	$	37,713		$	1,442			$	32,527		$	71,682
	Noncurrent liabilities	75,977			18,619				1,232			95,828
	Total liabilities	113,690			20,061				33,759			167,510
	Net assets	$	177,677		$	130,437			$	73,466		$	381,580
	Employees
	At December 31, 2014, we had approximately 1,080 employees, including approximately 540 employees outside the U.S. Approximately 130 of the employees in Canada and Mexico are represented by labor unions and are subject to collective bargaining agreements governing their employment with us. Of these employees, approximately 70 are subject to collective bargaining agreements that renew annually and 60 have collective bargaining agreements that expire in January 2016. We have never had a labor related work stoppage and believe our employee relations are good.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES
	Income tax expense (benefit)
	Our consolidated income from continuing operations before income taxes was generated in the following jurisdictions (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	U.S.	$	39,231		$	40,002		$	21,498
	Foreign	59,340			8,497			5,382
	Consolidated	$	98,571		$	48,499		$	26,880
	The following table summarizes income tax provision (benefit) from continuing operations by jurisdiction (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	Current income tax provision:
	Foreign	$	10,430		$	15,546		$	9,662
	U.S. federal	(195		)	2,067			—
	U.S. state	132			1,435			74
		10,367			19,048			9,736
	Deferred income tax provision (benefit):
	Foreign	2,024			(10,222		)	(12,070		)
	U.S. federal	30,074			(23,756		)	222
	U.S. state	4,048			(2,324		)	34
		36,146			(36,302		)	(11,814		)
	Provision (benefit) for income taxes	$	46,513		$	(17,254	)	$	(2,078	)
	The following table reconciles income tax provision at the U.S. federal statutory rate to the consolidated provision (benefit) for income taxes (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	Income from continuing operations before income taxes	$	98,571		$	48,499		$	26,880
	U.S. federal statutory rate	35		%	35		%	35		%
	Provision at statutory rate	34,500			16,975			9,408
	State income taxes—net of federal benefit	3,197			(577		)	71
	Effect of rates other than statutory	(1,925		)	(1,041		)	(829		)
	Effect of U.S. taxation on foreign branches	20,769			2,974			1,883
	Foreign tax adjustment, prior years	(3,669		)	4,533			—
	Warrants	4,698			24,625			—
	Noncontrolling interest	(7,986		)	(6,096		)	(3,429		)
	Foreign tax credit and offset to branch deferreds	6,851			(2,876		)	(12,360		)
	Impact of valuation allowance on deferred tax assets	(7,331		)	(53,218		)	6,233
	Foreign net gain on subsidiary dissolution and debt waivers	(13,620		)	—			—
	Foreign withholding taxes	5,054			—			—
	Other, net	5,975			(2,553		)	(3,055		)
	Provision (benefit) for income taxes	$	46,513		$	(17,254	)	$	(2,078	)
	For the years ended December 31, 2014, 2013, and 2012, , the foreign subsidiaries are disregarded entities for U.S. federal income tax purposes. The foreign earnings are taxed in foreign jurisdictions as well as in the U.S. Foreign tax credits, subject to limitations, are available to reduce U.S. taxes. The rate for 2014 is impacted by disallowance of a foreign loss on cross jurisdictional intercompany debt waivers which had no net impact to U.S. taxes and by the disallowance of an intercompany foreign gain on subsidiary dissolution. We have recorded foreign tax benefit in 2014 primarily related to the closure of a tax audit by Canada Revenue Agency with respect to 2009. Canadian withholding taxes of $5.1 million were incurred on the settlement of certain historical cross border intercompany balances during the year.
	Deferred tax positions
	Deferred income taxes reflect the effects of temporary differences between the amounts of assets and liabilities recognized for financial reporting purposes and the amounts recognized for income tax purposes. Significant components of deferred tax assets and liabilities are as follows at December 31, 2014 and 2013 (in thousands):
		December 31,			December 31,
		2014			2013
	Deferred tax assets:
	Net operating loss and other credit carryforwards	$	38,835		$	9,498
	Compensation and benefits	10,736			7,991
	Inventories	280			118
	Intangible assets	43,977			44,444
	Pension plan	3,733			2,849
	Allowance for doubtful accounts	1,860			2,140
	Deferred revenue	7,622			5,910
	Foreign tax credit and offset to branch deferreds	102,286			95,435
	Other	17,786			8,243
	less: valuation allowance	(102,769		)	(95,438		)
	Net deferred tax assets	124,346			81,190
	Deferred tax liabilities:
	Intangible assets	(5,770		)	(6,927		)
	Prepaid expenses	(163		)	(153		)
	Property, plant and equipment	(178,505		)	(113,030		)
	Equity investment in partnerships	(78,813		)	(49,720		)
	Other	(2,549		)	(1,471		)
	Total deferred tax liabilities	(265,800		)	(171,301		)
	Net deferred tax liabilities	$	(141,454	)	$	(90,111	)
	At December 31, 2014, we had a cumulative U.S. federal net operating loss of approximately $82.2 million that can be carried forward to apply against taxable income generated in future years. This carry forward begins to expire in 2031. We had cumulative U.S. state net operating losses of approximately $67.2 million available for carryforward, which begin to expire in 2016. We had a foreign net operating loss of $23.9 million available for indefinite carryforward. We had foreign tax credits of approximately $55.0 million available for carry forward, which begin to expire in 2020.
	Due to our emergence from bankruptcy and overall restructuring, we recorded a full valuation allowance on all U.S. federal and state deferred tax assets in all periods prior to March 31, 2013. Deferred tax assets are reduced by a valuation allowance when a determination is made that it is more likely than not that some, or all, of the deferred tax assets will not be realized based on the weight of all available evidence. Evidence which is objectively verifiable carries a higher weight in the analysis. The ultimate realization of deferred tax assets is dependent upon the existence of sufficient taxable income of the appropriate character within the carryback and carryforward period available under the tax law. Sources of taxable income include future reversals of existing taxable temporary differences, future earnings and available tax planning strategies.
In 2013, we recorded a discrete tax benefit for the partial release of our valuation allowance. Gain recognition, for tax purposes, on the contribution of a one-third interest in SCPL to Rose Rock had a material impact to the available positive and objectively verifiable evidence and combined with other factors, resulted in the change in our assessment of recoverability of the deferred tax assets. We did not release the valuation allowance attributable to a small portion of our state net operating loss carryovers which have shorter carryover periods. We have not released the valuation allowance on the foreign tax credits due to the foreign tax credit limitation and the relative subjectivity of forecasts of the relational magnitude of U.S. and foreign taxable income in future periods, as well as the shorter carryover period available for the credits.
The valuation allowance increased by $7.3 million during 2014. The change related to a net increase of $6.8 million for Foreign tax credits and offset to branch deferreds and an increase of $0.5 million to offset certain state net operating losses with shorter carryover periods.
We have analyzed filing positions in all of the federal, state and foreign jurisdictions where we are required to file income tax returns and determined that no accruals related to uncertainty in tax positions are required. All income tax years of the Company ending after the emergence from bankruptcy remain open for examination in U.S. jurisdictions under general operation of the statute of limitations, including special provisions with regard to net operating loss carryovers. In foreign jurisdictions, all tax periods prior to the emergence from bankruptcy are closed. The statute of limitations has not been waived with respect to any foreign jurisdictions post emergence and tax periods are open for examination in accordance with the general statutes of each foreign jurisdiction. The Canada Revenue Agency audit of 2009 was closed during the year. Currently, there are no examinations in progress for our federal, state or foreign jurisdictions.

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt	LONG-TERM DEBT
	Our long-term debt consisted of the following (in thousands):
		December 31,		December 31,
		2014		2013
	SemGroup 7.50% senior unsecured notes	$	300,000	$	300,000
	SemGroup corporate revolving credit facility	35,000		70,000
	Rose Rock 5.625% senior unsecured notes	400,000		—
	Rose Rock credit facility	32,000		245,000
	SemMexico credit facility	—		—
	Capital leases	132		125
	Total long-term debt	767,132		615,125
	less: current portion of long-term debt	40		37
	Noncurrent portion of long-term debt	$	767,092	$	615,088
	SemGroup senior unsecured notes
	On June 14, 2013, we completed an offering of $300 million of 7.50% senior unsecured notes due 2021 (the “Notes”). The Notes are guaranteed by certain of our subsidiaries: SemGas, L.P., SemCanada, L.P., SemCanada II, L.P., SemMaterials, L.P., SemGroup Europe Holding, L.L.C., SemOperating G.P., L.L.C., SemMexico, L.L.C., SemDevelopment, L.L.C., Rose Rock Midstream Holdings, LLC, Wattenberg Holding, LLC, Glass Mountain Holding, LLC and Mid-America Midstream Gas Services, L.L.C. (collectively, the "Guarantors"). The guarantees of the Notes are full and unconditional and constitute the joint and several obligations of the Guarantors.
	The net proceeds from the offering were $294.0 million, after underwriters' fees. We used the net proceeds from the offering to (i) fund a portion of our acquisition on August 1, 2013, of all the outstanding equity interests in Mid-America Midstream Gas Services, L.L.C., a subsidiary of Chesapeake Energy Corporation, and (ii) during the second quarter of 2013, repay amounts borrowed under our revolving credit facility.
	The Notes are governed by an indenture, as supplemented, between the Company and its subsidiary Guarantors and Wilmington Trust, N.A., as trustee (the “Indenture”). The Indenture includes customary covenants, including limitations on our ability to incur additional indebtedness or issue certain preferred shares; pay dividends and make certain distributions, investments and other restricted payments; create certain liens; sell assets; enter into transactions with affiliates; enter into sale and lease-back transactions; merge, consolidate, sell or otherwise dispose of all or substantially all of our assets; and designate our subsidiaries as unrestricted under the Indenture.
	The Indenture includes customary events of default, including events of default relating to non-payment of principal and other amounts owing from time to time, failure to provide required reports, failure to comply with agreements in the indenture, cross payment-defaults to any material indebtedness, bankruptcy and insolvency events, certain unsatisfied judgments, and invalidation or cessation of the subsidiary guarantee of a significant subsidiary. A default would permit holders to declare the Notes and accrued interest due and payable.
	The Notes are effectively subordinated in right of payment to any of our, and the Guarantors', existing and future secured indebtedness to the extent of the value of the collateral securing such indebtedness and are structurally subordinated to the obligations of any subsidiary that is not a guarantor of the Notes.
	The Company may issue additional Notes under the Indenture from time to time, subject to the terms of the Indenture.
	Except as described below, the Notes are not redeemable at the Company's option prior to June 15, 2016. From and after June 15, 2016, the Company may redeem the Notes, in whole or in part, at the redemption prices (expressed as percentages of principal amount) set forth below, plus accrued and unpaid interest, if redeemed during the twelve-month period beginning on June 15 of each of the years indicated below:
	Year		Percentage
	2016		105.62%
	2017		103.75%
	2018		101.88%
	2019 and thereafter		100.00%
	Prior to June 15, 2016, the Company may, at its option, on one or more occasions, redeem up to 35% of the sum of the original aggregate principal amount of the Notes at a redemption price equal to 107.500% of the aggregate principal amount thereof, plus accrued and unpaid interest, with the net cash proceeds of one or more equity offerings of the Company, subject to certain conditions.
	Prior to June 15, 2016, the Company may also redeem all or part of the Notes at a price equal to the principal plus a premium equal to the greater of 1% of the principal or the excess of the present value of the June 15, 2016 redemption price from the table above plus all required interest payments due through June 15, 2016, computed using a discount rate based on a published United States Treasury Rate plus 50 basis points, over the principal value of such Note.
	In the event of a change of control, the Company is required to offer to repurchase the Notes at an amount equal to 101% of the principal plus accrued and unpaid interest.
	Interest on the Notes is payable in arrears on June 15th and December 15th to holders of record on June 1st and December 1st each year until maturity. For the year ended December 31, 2014 and 2013, we incurred $23.3 million and $12.7 million, respectively, of interest expense related to the Notes including the amortization of debt issuance costs. At December 31, 2014, we had $5.4 million of unamortized debt issuance costs related to the Notes included in other noncurrent assets on our consolidated balance sheet.
	At December 31, 2014, we were in compliance with the terms of the Notes.
	SemGroup corporate credit agreement
	Our revolving credit facility has a capacity of $500 million at December 31, 2014. This capacity may be used either for cash borrowings or letters of credit, although the maximum letter of credit capacity is $250 million. The credit agreement allows for the increase of the revolving commitments under the credit agreement by an aggregate amount of $300 million subject to the satisfaction of certain conditions. The agreement matures on December 11, 2018. Earlier principal payments may be required if we enter into certain transactions to sell assets or obtain new borrowings. We have the right to make additional principal payments without incurring any penalties for early repayment.
	Interest on revolving credit cash borrowings is charged at either a Eurodollar rate or an alternate base rate ("ABR"), at our election, plus, in each case an applicable margin. The applicable margin will range from 2.0% to 3.25% in the case of a Eurodollar loan, and from 1.0% to 2.25% in the case of an ABR loan, in each case, based on a leverage ratio specified in the agreement.
	At December 31, 2014, there were $35.0 million of outstanding revolving cash borrowings of which $15.0 million incurred interest at the ABR and $20.0 million incurred interest at the Eurodollar rate. The interest rate in effect at December 31, 2014 on alternate base rate borrowings was 4.25%. The interest rate in effect at December 31, 2014 on Eurodollar rate borrowings was 2.23%.
	Fees are charged on any outstanding letters of credit at a rate that ranges from 2.0% to 3.25%, depending on a leverage ratio specified in the credit agreement. At December 31, 2014, we had $3.8 million of outstanding letters of credit for which the rate in effect was 2.0%. In addition, a fronting fee of 0.25% is charged on outstanding letters of credit.
	A commitment fee that ranges from 0.375% to 0.5%, depending on a leverage ratio defined in the credit agreement, is charged on any unused capacity on the revolving credit facility. In addition, we are charged an annual administrative fee of $0.1 million.
	At December 31, 2014, we had unamortized capitalized loan fees of $5.0 million net of accumulated amortization, which was recorded in other noncurrent assets and is being amortized over the life of the agreement.
	We recorded interest expense related to the revolving credit facility of $6.3 million, $7.7 million and $6.9 million for the years ended December 31, 2014, 2013 and 2012, respectively, including amortization of capitalized loan fees.
	The credit agreement includes customary affirmative and negative covenants, including limitations on the creation of new indebtedness, liens, sale and lease-back transactions, new investments, making fundamental changes including mergers and consolidations, making of dividends and other distributions, making material changes in our business, modifying certain documents and maintenance of a consolidated leverage ratio and an interest coverage ratio. In addition, the credit agreement prohibits any commodity transactions that are not permitted by our comprehensive risk management policy.
	The credit agreement includes customary events of default, including events of default relating to non-payment of principal and other amounts owing under the credit agreement from time to time, including in respect of letter of credit disbursement obligations, inaccuracy of representations and warranties in any material respect when made or when deemed made, violation of covenants, cross payment-defaults to any material indebtedness, cross acceleration to any material indebtedness, bankruptcy and insolvency events, the occurrence of a change of control, certain unsatisfied judgments, certain ERISA events, certain environmental matters and certain assertions of or actual invalidity of certain loan documents. A default under the credit agreement would permit the participating banks to terminate commitments, require immediate repayment of any outstanding loans with interest and any unpaid accrued fees, and require the cash collateralization of outstanding letter of credit obligations.
	The terms of our current credit facility restrict, to some extent, the payment of cash dividends on our common stock. The credit agreement is guaranteed by all of our material domestic subsidiaries (except for Rose Rock and its general partner and subsidiaries) and secured by a lien on substantially all of our property and assets, subject to customary exceptions.
	At December 31, 2014, we were in compliance with the terms of the credit agreement.
	Rose Rock senior unsecured notes
	On July 2, 2014, Rose Rock and its wholly-owned subsidiary, Rose Rock Finance Corporation ("Finance Corp."), as co-issuer, sold $400 million of 5.625% senior unsecured notes due 2022 (the “Rose Rock Notes”) to certain initial purchasers for resale to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”), and to non-U.S. persons outside the United States pursuant to Regulation S of the Securities Act. The Rose Rock Notes are guaranteed by all of Rose Rock's existing subsidiaries other than Finance Corp.
	The net proceeds from the offering of $391.9 million, after underwriters' fees and offering expenses, were used to repay amounts borrowed under Rose Rock's revolving credit facility and for general partnership purposes.
	The Rose Rock Notes are governed by an indenture between Rose Rock, its subsidiary guarantors, Finance Corp. and Wilmington Trust, National Association, as trustee (the “Rose Rock Indenture”). The Rose Rock Indenture includes customary covenants, including limitations on Rose Rock's ability to incur additional indebtedness or issue certain preferred shares; pay dividends and make certain distributions, investments and other restricted payments; create certain liens; sell assets; enter into transactions with affiliates; merge, consolidate, sell or otherwise dispose of all or substantially all of its assets; and designate its subsidiaries as unrestricted under the Rose Rock Indenture.
	The Rose Rock Indenture includes customary events of default. A default would permit the trustee or holders of at least 25% in aggregate principal amounts of the Rose Rock Notes then outstanding to declare all amounts owing under the Rose Rock Notes to be due and payable.
	The Rose Rock Notes are effectively subordinated in right of payment to any of Rose Rock's, and the subsidiary guarantors', existing and future secured indebtedness to the extent of the value of the collateral securing such indebtedness.
	Rose Rock may issue additional Rose Rock Notes under the Rose Rock Indenture from time to time, subject to the terms of the Rose Rock Indenture.
	Except as described below, the Rose Rock Notes are not redeemable at Rose Rock's option prior to July 15, 2017. From and after July 15, 2017, Rose Rock may redeem the Rose Rock Notes, in whole or in part, at the redemption prices (expressed as percentages of principal amount) set forth below, plus accrued and unpaid interest, if redeemed during the twelve-month period beginning on July 15 of each of the years indicated below:
	Year		Percentage
	2017		104.22%
	2018		102.81%
	2019		101.41%
	2020 and thereafter		100.00%
	Prior to July 15, 2017, Rose Rock may, at its option, on one or more occasions, redeem up to 35% of the sum of the original aggregate principal amount of the Rose Rock Notes at a redemption price equal to 105.625% of the aggregate principal amount thereof, plus accrued and unpaid interest, with the net cash proceeds of one or more equity offerings of Rose Rock, or the parent of Rose Rock to the extent such net proceeds are contributed to Rose Rock, subject to certain conditions.
	Prior to July 15, 2017, Rose Rock may also redeem all or part of the Rose Rock Notes at a price equal to the principal plus a premium equal to the greater of 1% of the principal or the excess of the present value of the July 15, 2017 redemption price from the table above plus all required interest payments due through July 15, 2017, computed using a discount rate based on a published United States Treasury Rate plus 50 basis points, over the principal value of such Note.
	In the event of a change of control, Rose Rock is required to offer to repurchase the Rose Rock Notes at an amount equal to 101% of the principal plus accrued and unpaid interest.
	In accordance with a Registration Rights Agreement, in September 2014 Rose Rock filed a registration statement with the SEC, which was declared effective by the SEC on September 23, 2014, enabling holders of the Rose Rock Notes to exchange the Rose Rock Notes and related guarantees for registered notes (the "Exchange Notes") and guarantees that have substantially identical terms as the Rose Rock Notes and related guarantees. The exchange offer expired on October 22, 2014. All of the Notes were exchanged. The guarantees of the Exchange Notes are full and unconditional and constitute the joint and several obligations of Rose Rock and its subsidiary guarantors.
	Interest on the Rose Rock Notes is payable in arrears on January 15th and July 15th to holders of record on January 1st and July 1st each year until maturity. For the year ended December 31, 2014, we incurred $11.7 million of interest expense related to the Rose Rock Notes including amortization of debt issuance costs. At December 31, 2014, we had $8.0 million of unamortized debt issuance costs related to the Notes included in other noncurrent assets on our consolidated balance sheet.
	At December 31, 2014, we were in compliance with the terms of the Rose Rock Indenture.
	Rose Rock credit facility
	Our Rose Rock senior secured revolving credit facility agreement provides for a revolving credit facility of $585 million and includes a $150 million sub-limit for letters of credit. The credit agreement was amended to extend the agreement to September 20, 2018 and permit the increase of the facility by not more than $200 million, subject to certain conditions. The agreement allows Rose Rock to incur unsecured or subordinated debt without limitation, subject to certain conditions, and provides alternative financial performance covenants at Rose Rock's election after the issuance of $200 million or more unsecured or subordinated debt, in aggregate. Subsequent to the issuance of the Rose Rock Notes, Rose Rock elected to adhere to the alternative financial performance covenants.
At Rose Rock’s option, amounts borrowed under the credit agreement will bear interest at either the Eurodollar rate or an ABR, plus, in each case, an applicable margin. The applicable margin will range from 1.75% to 3.00% in the case of a Eurodollar rate loan, and from 0.75% to 2.00% in the case of an ABR loan, in each case, based on a leverage ratio specified in the credit agreement. At December 31, 2014, we had outstanding cash borrowings of $32.0 million, of which $20.0 million incurred interest at the Eurodollar rate plus an applicable margin and $12.0 million incurred interest at the ABR plus an applicable margin. The interest rates at December 31, 2014 were 2.74% for Eurodollar borrowings and 4.75% for ABR borrowings.
Fees are charged on any outstanding letters of credit at a rate that ranges from 1.75% to 3.00%, depending on a leverage ratio specified in the credit agreement. At December 31, 2014, there were $17.5 million in outstanding letters of credit, and the rate in effect was 2.50%. In addition, a fronting fee of 0.25% is charged on outstanding letters of credit.
A commitment fee that ranges from 0.375% to 0.50%, depending on a leverage ratio specified in the credit agreement, is charged on any unused capacity of the revolving credit facility. In addition, we are charged an annual administrative fee of $0.1 million. The credit facility also allows for the use of Secured Bilateral Letters of Credit, which are issued external to the credit facility and do not reduce revolver availability. At December 31, 2014, we had $67.6 million of Bilateral Letters of Credit outstanding and the interest rate in effect was 1.75%.
At December 31, 2014, we had $3.8 million in capitalized loan fees, net of accumulated amortization, which is recorded in other noncurrent assets and is being amortized over the life of the agreement.
We recorded interest expense related to this facility of $9.0 million, $8.7 million and $1.9 million for the years ended December 31, 2014, 2013 and 2012, respectively, including amortization of debt issuance costs and interest on bilateral letters of credit.
The credit agreement includes customary representations and warranties and affirmative and negative covenants. The covenants in the agreement include limitations on creation of new indebtedness and liens, entry into sale and lease-back transactions, investments, and fundamental changes including mergers and consolidations, dividends and other distributions, material changes in Rose Rock’s business and modifying certain documents. In addition, the agreement prohibits any commodity transactions that are not permitted by Rose Rock’s comprehensive risk management policy.
The agreement, subsequent to Rose Rock's election to adhere to the alternative financial performance covenants requires Rose Rock to maintain a minimum ratio of consolidated EBITDA to consolidated cash interest expense at the end of any fiscal quarter, for the immediately preceding four quarter period, of 2.50 to 1.00 and a maximum ratio of consolidated net debt to consolidated EBITDA at the end of any fiscal quarter, for the immediately preceding four quarter period, of 5.50 to 1.00, and a maximum ratio of senior secured debt to consolidated EBITDA of 3.50 to 1.00.
The credit agreement includes customary events of default, including events of default relating to non-payment of principal and other amounts owing under the agreement from time to time, including in respect of letter of credit disbursement obligations, inaccuracy of representations and warranties in any material respect when made or when deemed made, violation of covenants, cross payment-defaults of Rose Rock and its restricted subsidiaries to any material indebtedness, cross acceleration to any material indebtedness, bankruptcy and insolvency events, the occurrence of a change of control, certain unsatisfied judgments, certain ERISA events, certain environmental matters and certain assertions of or actual invalidity of certain loan documents. A default under the Rose Rock credit agreement would permit the participating banks to terminate commitments, require immediate repayment of any outstanding loans with interest and any unpaid accrued fees, and require the cash collateralization of outstanding letter of credit obligations.
The credit agreement restricts Rose Rock’s ability to make certain types of payments relating to its units, including the declaration or payment of cash distributions; provided that Rose Rock may make quarterly distributions of available cash so long as no default under the agreement then exists or would result therefrom. The agreement is guaranteed by all of Rose Rock’s material domestic subsidiaries and secured by a lien on substantially all of the property and assets of Rose Rock and the guarantors, subject to customary exceptions.
At December 31, 2014, we were in compliance with the terms of the credit agreement.
SemMexico facilities
At December 31, 2014, SemMexico had no outstanding borrowings on its 44 million Mexican pesos (U.S. $3.0 million at the December 31, 2014 exchange rate) credit facility, which matures in May 2015. Borrowings are unsecured and bear interest at the bank prime rate in Mexico plus 1.5%.
At December 31, 2014, SemMexico had no outstanding borrowings on its 56 million Mexican pesos (U.S. $3.8 million at the December 31, 2014 exchange rate) credit facility, which matures in July 2015. Borrowings are unsecured and bear interest at the bank prime rate in Mexico plus 1.5%.
At December 31, 2014, SemMexico had outstanding letters of credit of 292.8 million Mexican pesos (U.S. $19.8 million) and a $3.0 million USD letter of credit. Fees charged on outstanding letters of credit generally range from 0.4% to 0.7%.
SemMexico recorded interest expense of $0.2 million, $0.2 million and $0.4 million during the years ended December 31, 2014, 2013 and 2012, respectively.
At December 31, 2014, we were in compliance with the terms of these facilities.
Scheduled principal payments
The following table summarizes the scheduled principal payments as of December 31, 2014 (in thousands). As described above, our debt agreements require accelerated principal payments under certain circumstances. As a result, principal payments may occur earlier than shown in the table below.
	Senior Unsecured Notes		Rose Rock Notes		SemGroup		Rose Rock		SemMexico		Capital		Total
					Facility		Facility		Facility		Leases
For the year ended:
31-Dec-15	$	—	$	—	$	—	$	—	$	—	$	40	$	40
31-Dec-16	—		—		—		—		—		40		40
31-Dec-17	—		—		—		—		—		26		26
31-Dec-18	—		—		35,000		32,000		—		26		67,026
31-Dec-19	—		—		—		—		—		—		—
Thereafter	300,000		400,000		—		—		—		—		700,000
Total	$	300,000	$	400,000	$	35,000	$	32,000	$	—	$	132	$	767,132
Fair value
We estimate the fair value of the Notes to be $299 million and the fair value of the Rose Rock Notes to be $368 million at December 31, 2014, based on unadjusted, transacted market prices, which is categorized as a Level 1 measurement. We estimate that the fair value of our other long-term debt was not materially different than the recorded values at December 31, 2014. It is our belief that neither the market interest rates nor our credit profile have changed significantly enough to have had a material impact on the fair value of our other debt outstanding at December 31, 2014. This estimate is categorized as a Level 2 measurement.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	Bankruptcy matters
	On July 22, 2008 (the "Petition Date"), SemGroup, L.P. and certain subsidiaries filed petitions for reorganization under Chapter 11 of the U.S. Bankruptcy Code. Also on July 22, 2008, SemGroup, L.P.'s Canadian subsidiaries filed for creditor protection in Canada. Later during 2008, certain other U.S. subsidiaries filed petitions for reorganization. While in bankruptcy, SemGroup, L.P. filed a plan of reorganization with the court, which was confirmed on October 28, 2009 (the "Plan of Reorganization"). The Plan of Reorganization determined, among other things, how pre-Petition Date obligations would be settled, the equity structure of the reorganized company upon emergence, and the financing arrangements upon emergence. SemGroup Corporation emerged from bankruptcy protection on November 30, 2009 (the "Emergence Date").
	Claims reconciliation process
	A large number of parties made claims against us for obligations alleged to have been incurred prior to our predecessor's bankruptcy filing. We have resolved or settled all of these outstanding claims and have made all required distributions. The Plan of Reorganization has therefore been fully administered.
	On November 7, 2014, SemGroup Corporation and the other reorganized debtors moved for a final decree from the bankruptcy court closing the debtors’ bankruptcy cases. The United States Bankruptcy Court for the District of Delaware granted the request and entered its Order Granting Motion of Remaining Debtors for Entry of Final Decree on December 18, 2014. Accordingly, the bankruptcy cases for SemCrude, L.P., Eaglwing, L.P., SemCanada II, L.P., SemCanada L.P., SemGas, L.P., SemGroup, L.P., SemMaterials, L.P., and SemStream, L.P. have been closed. As part of its decree, the Court retained jurisdiction over certain on-going adversary proceedings, but the debtors have estimated and paid the claims associated with these remaining adversaries, leaving the non-debtor parties to the adversaries to resolve their remaining claims amongst themselves.
	On January 2, 2015, Bettina M. Whyte, the duly appointed Trustee of the SemGroup Litigation Trust (the “Litigation Trustee”), filed a notice of appeal of the Bankruptcy Court’s December 18, 2014 order closing the aforementioned bankruptcy cases. However, the Bankruptcy Court’s order of final decree was effective upon entry, and the appeal does not stay the effect of the order. The Litigation Trustee’s appeal to the United States District Court for the District of Delaware is currently pending and will be opposed by SemGroup Corporation and the other remaining reorganized debtors.
	Dimmit County, TX claims
	An employee of Rose Rock Midstream Field Services, LLC was involved in a tractor trailer accident on January 15, 2015 in Dimmit County, Texas.  A second accident followed resulting in six fatalities and multiple injuries. At this time, the following lawsuits have been filed in either the District Court of Zavala County, Texas or the District Court of Dimmit County, Texas, Olga D. Rubio and Carlos Rubio, Individually and on Behalf of All Statutory Wrongful Death Beneficiaries of Carlos Rubio, Jr., Deceased vs. Rose Rock Midstream Field Services, LLC and Jesus T. Riojas; David Rodriguez and Maribel Rodriguez vs. Rose Rock Midstream Field Services, LLC and Jesus T. Riojas; David Rodriguez and Maribel Rodrigues, Plaintiffs and Alejandra Abigail Ortega, Individually and as next friend of K.A.P., a minor, and as Representative of the Estate of Eduardo Pena, and Julian Pena and Nelva G. Suifuentes Pena Intervenors vs. Rose Rock Midstream Field Services, LLC, Jesus Riojas, and Roberto Rivera; Derek Muhlenbruch vs. Rose Rock Midstream Field Services, LLC and Jesus T. Riojas; and Agustin Lara, Sr., Individually, and Elsa Zamarripa, Individually and As Representative of the Estate of Justin Lara, Deceased vs. Rose Rock Midstream Field Services, LLC and Jesus T. Riojas.  It is anticipated that additional lawsuits will be brought on behalf of the other deceased and injured parties.  We are currently working with counsel for the interested parties to investigate the accident, and no determination of liability has been made.  We will continue to defend our position and believe that any liability that may arise from this incident will be covered by our insurance; however, we cannot predict the outcome.
	Blueknight claim
	Blueknight Energy Partners, L.P. ("Blueknight"), which was formerly a subsidiary of SemGroup, together with other entities related to Blueknight, entered into a Shared Services Agreement on April 7, 2009, with SemCrude, L.P., now known as Rose Rock Midstream Crude, L.P. ("SemCrude") and SemManagement, L.L.C. (which are currently subsidiaries of SemGroup). The services provided by SemCrude to Blueknight under this agreement included assisting Blueknight with movement of crude oil belonging to Blueknight’s customers and with the operation of Blueknight’s Oklahoma pipeline system and its Cushing, Oklahoma terminal. Under the subsequent amendments to the agreements beginning in May 2010, certain of these services were phased out, and Blueknight began to perform all services necessary for the movement of its crude oil and the operation of its Cushing terminal without SemCrude’s assistance.
	In a letter dated August 18, 2011, Blueknight claimed that SemCrude owes Blueknight approximately 141,000 barrels of crude oil. We responded to Blueknight’s letter denying their charges and requesting documentation from Blueknight of its claim. On February 14, 2012, after months of interaction between the parties through which Blueknight was requested to substantiate its claim, Blueknight filed suit against SemCrude and other related companies in the District Court of Oklahoma County, Oklahoma. On May 1, 2012, the case was transferred to Tulsa County, Oklahoma. On July 2, 2012, the Tulsa County District Court appointed a Special Master to review terminal operations accounting records and determine whether 141,000 barrels of crude oil owned by Blueknight is missing after three months of operations in April through June, 2010. On June 11, 2013, the Special Master’s Report was filed with the District Court finding a shortage in Blueknight’s Cushing terminal and Oklahoma pipeline system of 148,000 barrels. However, after a review of all records created during that three month time period, the Special Master was unable to determine how the shortage might have occurred and was unable to determine the ownership of the potential shortage.
	We are currently seeking discovery in the District Court of documentation and testimony on the potential cause and the impact, if any, of the shortage found by the Special Master. We believe Blueknight’s causes of action to be without merit and will continue to defend our position; however, we cannot predict the outcome.
	Environmental
	We may from time to time experience leaks of petroleum products from our facilities and, as a result of which, we may incur remediation obligations or property damage claims. In addition, we are subject to numerous environmental regulations. Failure to comply with these regulations could result in the assessment of fines or penalties by regulatory authorities.
	The Kansas Department of Health and Environment ("the KDHE") initiated discussions during our bankruptcy proceeding regarding six of our sites in Kansas (five owned by Crude and one owned by SemGas) that KDHE believes, based on their historical use, may have soil or groundwater contamination in excess of state standards. KDHE sought our agreement to undertake assessments of these sites to determine whether they are contaminated. We reached an agreement with KDHE on this matter and entered into a Consent Agreement and Final Order with KDHE to conduct environmental assessments on the sites and to pay KDHE’s costs associated with their oversight of this matter. We have conducted Phase II investigations at all sites. Four of the sites have limited amounts of soil contamination that will be excavated and/or remediated on site. Four of the sites appeared to have ground water contamination requiring further delineation and/or ongoing monitoring. Work plans have been submitted to, and approved by, the KDHE. One site was closed and we anticipate closure in 2015 for three of the remaining five sites. We do not anticipate any penalties or fines for these historical sites.
	Other matters
	We are party to various other claims, legal actions, and complaints arising in the ordinary course of business. In the opinion of our management, the ultimate resolution of these claims, legal actions, and complaints, after consideration of amounts accrued, insurance coverage, and other arrangements, will not have a material adverse effect on our consolidated financial position, results of operations or cash flows. However, the outcome of such matters is inherently uncertain, and estimates of our consolidated liabilities may change materially as circumstances develop.
	Asset retirement obligations
	We will be required to incur significant removal and restoration costs when we retire our natural gas gathering and processing facilities in Canada. We have recorded a liability associated with these obligations, which is reported within other noncurrent liabilities on the consolidated balance sheets. The following table summarizes the changes in this liability from December 31, 2011 through December 31, 2014 (in thousands):
	Balance, December 31, 2011	$	35,886
	Accretion	4,554
	Payments made	(1,169		)
	Currency translation adjustments	834
	Balance, December 31, 2012	40,105
	Accretion	4,752
	Payments made	(808		)
	Currency translation adjustments	(2,864		)
	Balance, December 31, 2013	41,185
	Accretion	4,807
	Payments made	(514		)
	Currency translation adjustments	(3,524		)
	Balance, December 31, 2014	$	41,954
	The December 31, 2014 liability was calculated using the $93.4 million cost we estimate we would incur to retire these facilities, discounted based on our risk-adjusted cost of borrowing and the estimated timing of remediation.
	The calculation of the liability for an asset retirement obligation requires the use of significant estimates, including those related to the length of time before the assets will be retired, cost inflation over the assumed life of the assets, actual remediation activities to be required, and the rate at which such obligations should be discounted. Future changes in these estimates could result in material changes in the value of the recorded liability. In addition, future changes in laws or regulations could require us to record additional asset retirement obligations. The $93.4 million estimated cost represents only our proportionate share of the obligations associated with these facilities. An additional $37.7 million of estimated costs are attributable to third-party owners’ proportionate share of the obligations. If an owner fails to perform on its obligations, the other owners (including SemGroup) could be obligated to bear that party’s share of the remediation costs.
	Our other segments may also be subject to removal and restoration costs upon retirement of their facilities. However, we are unable to predict when, or if, our pipelines, storage tanks and other facilities would become completely obsolete and require decommissioning. Accordingly, we have not recorded a liability or corresponding asset, as both the amount and timing of such potential future costs are indeterminable.
	Operating leases
	We have entered into operating lease agreements for office space, office equipment, land and trucks. Future minimum payments required under operating leases that have initial or remaining non-cancellable lease terms in excess of one year at December 31, 2014 are as follows (in thousands):
	For year ending:
	31-Dec-15	$	9,464
	31-Dec-16	9,181
	31-Dec-17	6,737
	31-Dec-18	2,997
	31-Dec-19	1,826
	Thereafter	6,967
	Total future minimum lease payments	$	37,172
	We recorded lease and rental expenses of $16.2 million, $11.4 million and $8.4 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Purchase and sale commitments
	We routinely enter into agreements to purchase and sell petroleum products at specified future dates. We account for these commitments as normal purchases and sales, and therefore we do not record assets or liabilities related to these agreements until the product is purchased or sold. At December 31, 2014, such commitments included the following (in thousands):
		Volume			Value
		(barrels)
	Fixed price purchases	13,648			$	1,141,694
	Fixed price sales	13,612			$	1,152,966
	Floating price purchases	7,187			$	373,539
	Floating price sales	10,719			$	445,655
	Certain of the commitments shown in the table above relate to agreements to purchase product from a counterparty and to sell a similar amount of product (in a different location) to the same counterparty. Many of the commitments shown in the table above are cancellable by either party, as long as notice is given within the time frame specified in the agreement (generally 30 to 120 days).
	Our SemGas segment has a take or pay contractual obligation related to the fractionation of natural gas liquids. This obligation continues through June 2023, subsequent to the extension of the agreement in the second quarter of 2013. At December 31, 2014, approximately $25.8 thousand was due under the contract. The approximate amount of future obligation is as follows (in thousands):
	For year ending:
	31-Dec-15	$	10,199
	31-Dec-16	11,804
	31-Dec-17	11,938
	31-Dec-18	10,060
	31-Dec-19	9,121
	Thereafter	24,391
Total expected future payments	$	77,513
SemGas further has a take or pay contractual obligation related to pipeline transportation. This obligation began in April 2014 and continues through October 2015. The amount of future obligation is approximately $2.6 million. SemGas also enters into contracts under which we are responsible for marketing the majority of the gas and natural gas liquids produced by the counterparties to the agreements. The majority of SemGas’ revenues were generated from such contracts.
Capital contribution requirements
See Note 5 for commitments related to the White Cliffs expansion project.

Equity

Equity	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Equity	EQUITY
	Common stock
	Upon emergence from bankruptcy, we issued 40,882,496 shares of common stock. The Plan of Reorganization specified that we were to issue an additional 517,500 shares of common stock in settlement of pre-petition claims. As of December 31, 2014, we have issued all of the shares of this stock. The par value of common stock reflected on the consolidated balance sheet at December 31, 2014 is summarized below:
	Shares issued on Emergence Date	40,882,496
	Shares subsequently issued in settlement of pre-petition claims	517,500
	Issuance of shares under employee and director compensation programs*	861,503
	Shares issued under employee stock purchase plan	6,999
	Shares issued upon exercise of warrants**	1,345,556
	Total shares***	43,614,054
	Par value per share	$	0.01
	Par value of common stock at December 31, 2014 (in thousands)	$	436
	* These shares include 169,340 shares which vested during the year ended December 31, 2014. Of these vested shares, recipients sold back to the Company 11,120 shares to satisfy tax withholding obligations which are being recognized at cost as treasury stock on the consolidated balance sheet.
	** These shares include 904,231 shares issued during the year ended December 31, 2014.
	*** In addition to the shares in the table above, there are shares of unvested restricted stock outstanding at December 31, 2014. The par value of these shares has not yet been reflected in common stock on the consolidated balance sheet, as these shares have not yet vested. There are also shares of restricted stock that were returned to treasury upon forfeiture. The par value of these shares is not reflected in the consolidated balance sheet, as no accounting recognition is given to forfeited shares. Certain unvested restricted stock is considered legally issued and outstanding and is included in the number of shares presented on the consolidated balance sheets.
	The common stock includes Class A and Class B stock. Class A stock is eligible to be listed on an exchange, whereas Class B stock is not. Any share of Class B stock may be converted to Class A at the election of the holder. Both classes of stock have full voting rights. Both classes of stock have a par value of $0.01 per share. On June 17, 2014, all Class B stock was converted to Class A. The total common stock outstanding at December 31, 2013 includes 28,235 shares of Class B stock. The total number of shares authorized for issuance is 90,000,000 shares of Class A stock and 10,000,000 shares of Class B stock.
	Warrants
	Upon emergence from bankruptcy protection, we issued 1,634,210 warrants. The Plan of Reorganization specified that we were to issue an additional 544,737 warrants in settlement of the pre-petition claims. As of December 31, 2014, we have issued all of the warrants. The warrants expired on November 30, 2014.
	Each warrant entitled the holder to purchase one share of common stock for $25 at any time before the November 30, 2014 expiration date. Upon exercise, a holder could elect a cashless exercise, whereby the number of shares to be issued to the holder was reduced, in lieu of a cash payment. For the year ended December 31, 2014, 1,271,983 warrants were exercised and 904,231 shares of common stock were issued.
	Dividends
	We began paying a quarterly cash dividend in the second quarter of 2013. The following table sets forth the quarterly dividends per share declared and paid to shareholders for the periods indicated:
	Quarter Ending	Dividend Per Share		Date Declared	Date of Record	Date Paid
	30-Jun-13	$	0.19	May 8, 2013	May 20, 2013	May 30, 2013
	30-Sep-13	$	0.2	August 8, 2013	August 19, 2013	August 30, 2013
	31-Dec-13	$	0.21	November 11, 2013	November 22, 2013	December 3, 2013
	31-Mar-14	$	0.22	February 25, 2014	March 10, 2014	March 20, 2014
	30-Jun-14	$	0.24	May 8, 2014	May 19, 2014	May 29, 2014
	30-Sep-14	$	0.27	August 6, 2014	August 18, 2014	August 28, 2014
	31-Dec-14	$	0.3	November 6, 2014	November 17, 2014	November 28, 2014
	31-Mar-15	$	0.34	February 26, 2015	March 9, 2015	March 20, 2015

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE
	Earnings per share is calculated based on income from continuing and discontinued operations less any income attributable to noncontrolling interests. Income attributable to noncontrolling interests represents third-party limited partner unitholders' interests in the earnings of our consolidated subsidiary, Rose Rock.  Rose Rock allocates net income to its limited partners based on the distributions pertaining to the current period's available cash as defined by Rose Rock's partnership agreement. After adjusting for the appropriate period's distributions, the remaining undistributed earnings or excess distributions over earnings, if any, are allocated to Rose Rock's general partner, limited partners and participating securities in accordance with the contractual terms of Rose Rock's partnership agreement and as further prescribed under the two-class method. Incentive distribution rights do not participate in undistributed earnings.
	Basic earnings (loss) per share is calculated based on the weighted average shares outstanding during the period. Diluted earnings (loss) per share includes the dilutive effect of warrants and unvested equity compensation awards.
	The following summarizes the calculation of basic earnings per share for the years ended December 31, 2014, 2013 and 2012 (in thousands, except per share amounts):
		Year Ended December 31, 2014
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	52,058	$	(1	)	$	52,057
	less: Income attributable to noncontrolling interest	22,817		—			22,817
	Income attributable to SemGroup	$	29,241	$	(1	)	$	29,240
	Weighted average common stock outstanding	42,665		42,665			42,665
	Basic earnings per share	$	0.69	$	0		$	0.69
		Year Ended December 31, 2013
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	65,753	$	59		$	65,812
	less: Income attributable to noncontrolling interest	17,710		—			17,710
	Income attributable to SemGroup	$	48,043	$	59		$	48,102
	Weighted average common stock outstanding	42,339		42,339			42,339
	Basic earnings per share	$	1.13	$	0		$	1.14
		Year Ended December 31, 2012
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	28,958	$	2,939		$	31,897
	less: Income attributable to noncontrolling interest	9,797		—			9,797
	Income attributable to SemGroup	$	19,161	$	2,939		$	22,100
	Weighted average common stock outstanding	41,939		41,939			41,939
	Basic earnings per share	$	0.46	$	0.07		$	0.53
	The following summarizes the calculation of diluted earnings per share for the years ended December 31, 2014, 2013 and 2012 (in thousands, except per share amounts):
		Year Ended December 31, 2014
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	52,058	$	(1	)	$	52,057
	less: Income attributable to noncontrolling interest	22,817		—			22,817
	Income attributable to SemGroup	$	29,241	$	(1	)	$	29,240
	Weighted average common stock outstanding	42,665		42,665			42,665
	Effect of dilutive securities	302		302			302
	Diluted weighted average common stock outstanding	42,967		42,967			42,967
	Diluted earnings per share	$	0.68	$	0		$	0.68
		Year Ended December 31, 2013
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	65,753	$	59		$	65,812
	less: Income attributable to noncontrolling interest	17,710		—			17,710
	Income attributable to SemGroup	$	48,043	$	59		$	48,102
	Weighted average common stock outstanding	42,339		42,339			42,339
	Effect of dilutive securities	307		307			307
	Diluted weighted average common stock outstanding	42,646		42,646			42,646
	Diluted earnings per share	$	1.13	$	0		$	1.13
		Year Ended December 31, 2012
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	28,958	$	2,939		$	31,897
	less: Income attributable to noncontrolling interest	9,797		—			9,797
	Income attributable to SemGroup	$	19,161	$	2,939		$	22,100
	Weighted average common stock outstanding	41,939		41,939			41,939
	Effect of dilutive securities	315		315			315
	Diluted weighted average common stock outstanding	42,254		42,254			42,254
	Diluted earnings per share	$	0.45	$	0.07		$	0.52
	All outstanding warrants expired on November 30, 2014 and therefore have no dilutive effect for the year ended December 31, 2014. For the years ended December 31, 2013 and 2012, we recorded a loss on the change in the fair value of the warrants; because of this, the warrants did not cause any dilution for that period.

EquityBased_Compensation

Equity-Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity-Based Compensation	EQUITY-BASED COMPENSATION
	SemGroup Corporation equity awards
	We have reserved a total of 2,781,635 shares of common stock for issuance pursuant to employee and director compensation programs. These awards give the recipients the right to receive shares of common stock, once specified service, performance or market related vesting conditions are met. The awards typically have one year vesting period for non-management directors and three years for employees. The awards may be subject to accelerated vesting in the event of involuntary terminations. We record expense for these awards (and corresponding increases to additional paid-in capital) based on the grant date fair value of the awards over the vesting period. We use authorized but unissued shares to satisfy our equity-based payment obligations. Although these awards are to be settled in shares, we may elect to give participants the option of settling a portion of the awards in cash, to meet statutory minimum tax withholding requirements. The activity related to these awards during the period from December 31, 2011 to December 31, 2014 is summarized below:
		Unvested			Average		Aggregate Fair Value of Shares (in thousands)
		Shares			Grant Date
					Fair Value
	Outstanding at December 31, 2011	410,506			$	26.59
	Awards granted - 2012	246,432			$	27.81
	Awards vested - 2012	(162,986	)		$	25.2	$	4,107
	Awards forfeited - 2012	(43,400	)		$	27.74
	Outstanding at December 31, 2012	450,552			$	26.87
	Awards granted - 2013	201,451			$	52.78
	Awards vested - 2013	(107,988	)		$	25.71	$	2,776
	Awards forfeited - 2013	(13,412	)		$	32.36
	Outstanding at December 31, 2013	530,603			$	36.8
	Awards granted - 2014	207,786			$	77.14
	Awards vested - 2014	(169,340	)		$	33.07	$	5,600
	Awards forfeited - 2014	(119,130	)		$	42.16
	Outstanding at December 31, 2014	449,919			$	70.69
	For certain of the awards granted in 2014, 2013 and 2012, the number of shares that will vest is contingent upon our achievement of certain specified targets. Awards with performance conditions are valued based on the grant date closing price on the New York Stock Exchange assuming that 100% of the awards will vest. Awards with market conditions are valued using Monte Carlo simulations. The following table sets forth the assumptions used in the valuations of these awards granted in 2014, 2013 and 2012:
		2014		2013
	Volatility	29.30%		28.90%
	Risk-free interest rate	0.66%		0.35%
	Volatility assumptions related to 2014 awards containing a market condition were based on historical volatility using a simple average calculation of volatility over a period equal to the vesting period of the awards.  We do not expect future volatility over the term of the awards to be significantly different from historical volatility.  Volatility assumptions related to 2013 awards containing a market condition were comprised of 50% historical volatility and 50% implied volatility.  We intend to use only historical volatility going forward.  The change in assumption basis from 2014 to 2013 did not have a significant impact.  The 2012 awards with a market condition were not material and were valued based on the grant date fair value and an estimate of the expected achievement of the market condition.
	If we meet the specified maximum targets, approximately 54 thousand, 49 thousand and 25 thousand additional shares could vest related to the 2014, 2013 and 2012 awards, respectively.
	During the month of January 2015, 102,103 awards vested. Of these vested awards, 36,564 shares were withheld to satisfy minimum tax withholding requirements.
	The holders of certain restricted stock awards granted prior to 2013 are entitled to equivalent dividends (“UDs”) to be received upon vesting of the restricted stock awards. The dividends will be settled in common shares based on the market price of our Class A shares as of the close of business on the vesting date. The UDs are subject to the same forfeiture and acceleration conditions as the associated restricted stock awards. For the year ended December 31, 2014, 593 units were issued upon the vesting of these restricted units. For the year ended December 31, 2013, no units were issued upon the vesting of these restricted units. At December 31, 2014, the value of the UDs related to unvested restricted stock awards was approximately $155 thousand. This is equivalent to 2,263 Class A shares based on the year end close of business market price of our Class A shares of $68.39 per share. Dividends related to the 2013 and 2014 restricted stock awards will be settled in cash upon vesting. At December 31, 2014, the value of UDs to be settled in cash related to unvested restricted stock awards was approximately $244 thousand.
	In January 2015, the 2012 restricted stock awards vested and 1,793 UD shares were issued.
	Compensation costs expensed for the years ended December 31, 2014, 2013 and 2012 were $7.3 million, $6.5 million and $6.2 million, respectively. As of December 31, 2014, there was $14.2 million of total unrecognized compensation cost related to our non-vested awards, which is expected to be recognized over a weighted-average period of 18 months.
	Employee stock purchase plan
	Our employee stock purchase plan ("ESPP") allows eligible employees to contribute up to 10% of their base earnings toward the semi annual purchase of our common stock, subject to an annual maximum dollar amount. The purchase price is 85% of the closing price on the last business day of the offering period. We have reserved a total of 1,000,000 shares of common stock for issuance under the ESPP. During the year ended December 31, 2014, we issued 6,999 shares under our ESPP.
	Rose Rock Midstream L.P. equity-based compensation
	Certain of our employees who support Rose Rock participate in Rose Rock's equity-based compensation program. Awards under this program generally represent awards of restricted common units representing limited partner interests of Rose Rock. Generally, the awards vest three years after the date of grant for employees and one year after the date of grant for non-management directors, contingent upon the continued service of the recipients and may be subject to accelerated vesting in the event of involuntary terminations. Awards are valued based on the grant date closing price listed on the New York Stock Exchange. Compensation expense is recognized over the vesting period and is discounted for estimated forfeitures. Vesting of these awards dilutes our ownership interest and requires additional equity contributions to Rose Rock to maintain our 2% general partner interest.  The activity related to these awards is summarized below:
		Unvested Units			Average Grant Date Fair Value		Aggregate Fair Value of Units (in thousands)
	Outstanding at December 31, 2011	—			$	—
	Awards granted - 2012	46,069			$	21.97
	Awards vested - 2012	—			$	—	$	—
	Awards forfeited - 2012	(2,109	)		$	20.6
	Outstanding at December 31, 2012	43,960			$	21.91
	Awards granted - 2013	49,104			$	34.41
	Awards vested - 2013	(9,333	)		$	27.25	$	254
	Awards forfeited - 2013	(783	)		$	34.4
	Outstanding at December 31, 2013	82,948			$	28.59
	Awards granted - 2014	46,536			$	41.35
	Awards vested - 2014	(5,712	)		$	35.87	$	205
	Awards forfeited - 2014	(21,432	)		$	29.82
	Outstanding at December 31, 2014	102,340			$	33.79
	During the month of January 2015, 25,745 of these awards vested. Of these vested awards, 10,537 units were withheld to satisfy minimum tax requirements.
	Compensation cost expensed for the years ended December 31, 2014, 2013 and 2012 was $0.9 million, $0.8 million and $0.3 million, respectively, and represents an increase in noncontrolling interests in consolidated subsidiaries.  As of December 31, 2014, there was $1.8 million of total unrecognized compensation cost related to the non-vested awards, which is expected to be recognized over a weighted-average period of 19 months.
	The holders of certain of these restricted unit awards granted prior to 2013 are entitled to equivalent distributions (“Unvested Unit Distributions” or “UUD’s”) to be received upon vesting of the restricted unit awards. The distributions will be settled in common units based on the market price of Rose Rock's limited partner common units as of the close of business on the vesting date. The UUD’s are subject to the same forfeiture and acceleration conditions as the associated restricted units. For the year ended December 31, 2014, no UUDs were issued upon the vesting of these restricted units. For the year ended December 31, 2013, 406 UUDs were issued upon the vesting of these restricted units. At December 31, 2014, the value of the UUD’s was approximately $129 thousand. This is equivalent to approximately 2,835 common units based on the year end close of business market price of Rose Rock's common units of $45.45 per unit. During the month of January 2015, 3,335 units were issued upon the vesting of restricted units noted above. Distributions related to the restricted unit awards granted subsequent to 2012 will be settled in cash upon vesting. At December 31, 2014, the value of these UUDs related to cash settled unvested restricted units was approximately $177 thousand.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS
	Defined contribution plans
	We sponsor defined contribution retirement plans in which the majority of employees are eligible to participate. Our contributions to the defined contribution plans were $1.9 million, $1.1 million, and $0.9 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Pension plans
	We sponsor a defined benefit pension plan and a supplemental defined benefit pension plan (collectively, the “Pension Plans”) for certain employees of the SemCAMS segment hired before June 30, 2001. The following table shows the projected benefit obligations and plan assets of the Pension Plans (in thousands):
		December 31,				December 31,
		2014				2013
	Change in projected benefit obligation:
	Projected benefit obligation at beginning of year	$	24,036			$	28,357
	Service cost	477				577
	Interest cost	1,080				1,047
	Actuarial (gains) losses	6,228				(3,022		)
	Benefits paid	(521		)		(968		)
	Currency translation adjustment	(2,034		)		(1,955		)
	Projected benefit obligation at end of year	29,266				24,036
	Change in fair value of plan assets:
	Fair value of plan assets at beginning of year	25,582				22,727
	Employer contributions	601				1,144
	Actual return on plan assets	2,915				4,397
	Benefits paid	(521		)		(968		)
	Currency translation adjustment	(2,209		)		(1,718		)
	Fair value of plan assets at end of year	26,368				25,582
	Funded status:	$	(2,898	)		$	1,546
	Accumulated benefit obligation at end of year	$	26,544			$	22,687
	The following table sets forth the assumptions used to determine the projected benefit obligation of the Pension Plans for the periods indicated:
		Year Ended December 31, 2014			Year Ended December 31, 2013
	Discount rate	3.8	%		4.7	%
	Compensation increase rate	4.5	%		3.5	%
	We recorded other noncurrent liabilities of $2.9 million at December 31, 2014, and other noncurrent assets of $1.5 million at December 31, 2013, to reflect the funded status of the Pension Plans. We recorded changes in the funded status of the Pension Plans to other comprehensive income (loss), net of income taxes. These amounts were a loss of $3.7 million for the year ended December 31, 2014, a gain of $4.8 million for the year ended December 31, 2013 and a loss of $0.4 million for the year ended December 31, 2012.
	The following table summarizes the components of the net periodic benefit cost related to the Pension Plans (in thousands):
		Year Ended December 31, 2014				Year Ended December 31, 2013				Year Ended December 31, 2012
	Service cost	$	477			$	577			$	596
	Interest cost	1,080				1,047				1,134
	Expected return on plan assets	(1,469		)		(1,298		)		(1,263		)
	Settlement loss	—				—				(55		)
	Other	(7		)		186				118
	Net periodic benefit cost	$	81			$	512			$	530
	The following table sets forth the assumptions used to determine net periodic benefit cost related to the Pension Plans for the periods indicated:
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	Discount rate	4.7	%		3.9	%		4.25	%
	Expected long-term rate of return on plan assets	6	%		6	%		6	%
	Compensation increase rate	3.5	%		3.5	%		3.5	%
	The expected return on plan assets is determined annually based upon a review of the historical returns experienced for each of the various classes of assets held within the plan, combined with the general economic industry outlook.
	We estimate that benefit payments from the Pension Plans will be as follows for the years 2015 – 2024 (in thousands):
	Year		Estimated
			Benefit Payments
	2015		$	4,800
	2016		$	2,809
	2017		$	2,046
	2018		$	987
	2019		$	1,114
	2020 - 2024		$	12,178
	We estimate that we will make contributions of $0.6 million to the Pension Plans during the year ended December 31, 2015.
	Substantially all of the plan’s assets are invested in pooled funds that hold highly-liquid securities. The value of each share of a pooled fund is calculated based on the quoted market prices of the assets held by the fund. The following table shows the value of each category of plan assets at December 31, 2014 and 2013 and the target investment allocation under our investment policy at December 31, 2014:
		Asset Value at				Asset Value at				Actual			Normal			Minimum			Maximum
		December 31,				December 31,				Allocation at			Allocation			Allocation			Allocation
		2014				2013				December 31,			Per			Per			Per
		(in thousands)				(in thousands)				2014			Investment			Investment			Investment
													Policy			Policy			Policy
	Cash and cash equivalents	$	—			$	171			0	%		—	%		0	%		10	%
	Pooled funds—fixed income	8,938				8,381				33.9	%		40	%		32.5	%		47.5	%
	Pooled funds—Canadian equities	8,828				8,324				33.5	%		30	%		22.5	%		37.5	%
	Pooled funds—non-Canadian equities	8,602				8,706				32.6	%		30	%		22.5	%		37.5	%
	Total	$	26,368			$	25,582
Our investment policy for plan assets permits investments in a wide variety of assets, including certain types of derivatives. Our policy prohibits investments of plan assets in certain types of assets, including commodities, mineral rights and collectibles. Our investment policy requires us to maintain an investment allocation within the ranges shown in the table above, and also contains more specific requirements that are designed to achieve an appropriate level of diversification.
The following information discloses the fair values of our Pension Plan assets, by asset category, for the periods indicated (in thousands):
	December 31, 2014										December 31, 2013
	Quoted Price in Active Markets for Identical Assets (Level 1)			Significant Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)				Quoted Price in Active Markets for Identical Assets (Level 1)			Significant Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
Cash and cash equivalents	$	—		$	—		$	—			$	171		$	—		$	—
Fixed income mutual funds (a)	—			8,938			—				—			8,381			—
Equity mutual funds (a)	—			17,430			—				—			17,030			—
Total	$	—		$	26,368		$	—			$	171		$	25,411		$	—
(a) Mutual funds are valued daily in actively traded markets by an independent custodian for the investment manager. For purposes of calculating the value, portfolio securities and other assets for which market quotes are readily available are valued at market value. Market value is generally determined on a basis of last reported sales prices, or if no sales are reported, based on quotes obtained from a quotation reporting system, established market makers, or pricing services. Investments initially valued in currencies other than the U.S. dollar are converted to the U.S. dollar using exchange rates obtained from pricing services.
Retiree medical plan
We sponsor an unfunded, post-employment health benefit plan (the “Health Plan”) for certain employees of the SemCAMS segment. The projected benefit obligation related to the Health Plan was $1.7 million at December 31, 2014 and $1.6 million at December 31, 2013, and is reported within other noncurrent liabilities on the consolidated balance sheets.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)
	The following table presents changes in the components of accumulated other comprehensive income (loss) (in thousands):
		Currency			Employee			Interest			Total
		Translation			Benefit			Rate Swaps
					Plans
	Balance, December 31, 2011	$	(10,780	)	$	(2,811	)	$	(284	)	$	(13,875	)
	Currency translation adjustment, net of income tax expense of $1,168	12,635			—			—			12,635
	Settlement of interest rate swaps	—			—			284			284
	Changes related to benefit plans, net of income tax benefit of $117	—			(343		)	—			(343		)
	Balance, December 31, 2012	1,855			(3,154		)	—			(1,299		)
	Currency translation adjustment, net of income tax benefit of $3,993	(6,363		)	—			—			(6,363		)
	Changes related to benefit plans, net of income tax expense of $1,603	—			4,808			—			4,808
	Balance, December 31, 2013	(4,508		)	1,654			—			(2,854		)
	Currency translation adjustment, net of income tax benefit of $11,102	(20,551		)	—			—			(20,551		)
	Changes related to benefit plans, net of income tax benefit of $1,245	—			(3,736		)	—			(3,736		)
	Balance, December 31, 2014	$	(25,059	)	$	(2,082	)	$	—		$	(27,141	)

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION
	Operating assets and liabilities
	The following table summarizes the changes in the components of operating assets and liabilities, net of the effects of acquisitions (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	Decrease (increase) in restricted cash	$	(2,045	)	$	29,467		$	4,907
	Decrease (increase) in accounts receivable	(32,602		)	11,172			(129,102		)
	Decrease (increase) in receivable from affiliates	50,454			(61,095		)	230
	Decrease (increase) in inventories	(6,243		)	(11,352		)	(936		)
	Decrease (increase) in derivatives and margin deposits	28			1,012			(1,245		)
	Decrease (increase) in other current assets	(614		)	9,361			4,197
	Decrease (increase) in other assets	2			137			2,467
	Increase (decrease) in accounts payable and accrued liabilities	11,461			31,030			114,776
	Increase (decrease) in payable to affiliates	(48,819		)	62,279			(6,871		)
	Increase (decrease) in payables to pre-petition creditors	(54		)	(29,609		)	(5,206		)
	Increase (decrease) in other noncurrent liabilities	5,067			(2,541		)	2,500
		$	(23,365	)	$	39,861		$	(14,283	)
	Non-cash transactions
	During the years ended December 31, 2014 and 2013, we recorded reductions of $85.2 million and $180.2 million, respectively, to noncontrolling interests in consolidated subsidiaries and offsetting increases to additional paid-in capital of $53.2 million and $112.9 million, respectively, (net of tax impacts of $31.9 million and $67.3 million, respectively). These non-cash entries represent the portion of proceeds in excess of historical cost which were attributed to Rose Rock's third-party unitholders related to Rose Rock's purchases of interests in SCPL (Note 4).
	During the years ended December 31, 2014 and 2013, we issued 904,231 and 425,618 shares of Class A common stock, respectively, related to the exercise of warrants. These issuances resulted in the non-cash reclassifications for the years ended December 31, 2014 and 2013 of $73.0 million and $21.4 million, respectively, from other noncurrent liabilities to common stock and additional paid-in capital. Cash proceeds of $1.5 million and $0.2 million were received in connection with the warrant exercises for the years ended December 31, 2014 and 2013, respectively.
	Other supplemental disclosures
	We paid cash for interest totaling $36.7 million, $23.9 million and $8.0 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	We paid cash for income taxes (net of refunds received) in the amount of $23.5 million, $13.9 million and $11.4 million during the years ended December 31, 2014, 2013 and 2012, respectively.
	We accrued $7.0 million, $10.1 million and $1.6 million at December 31, 2014, 2013 and 2012, respectively, for purchases of property, plant and equipment.
	We sold common units of NGL Energy for proceeds of $88.8 million during the year ended December 31, 2014 (Note 5). At December 31, 2014, only $79.7 million of proceeds from the sales had been received and the remaining amount is a non-cash accrual at December 31, 2014.

Quarterly_Financial_Data

Quarterly Financial Data	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Quarterly Financial Data (Unaudited)	QUARTERLY FINANCIAL DATA (UNAUDITED)
	Summarized information on our consolidated results of operations for the quarters during the year ended December 31, 2014 is shown below (in thousands, except per share amounts):
		First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	Total revenues	$	498,883		$	482,224		$	594,235		$	547,237		$	2,122,579
	Loss (gain) on disposal or impairment of long-lived assets, net	(58		)	19,315			1,376			11,959			32,592
	Other operating costs and expenses	478,264			471,863			575,936			530,150			2,056,213
	Total expenses	478,206			491,178			577,312			542,109			2,088,805
	Earnings from equity method investments	14,962			19,187			14,223			15,827			64,199
	Gain on issuance of common units by equity method investee	8,127			—			18,772			2,121			29,020
	Operating income	43,766			10,233			49,918			23,076			126,993
	Other expenses (income), net	7,497			29,489			(6,368		)	(2,196		)	28,422
	Income (loss) from continuing operations before income taxes	36,269			(19,256		)	56,286			25,272			98,571
	Income tax expense (benefit)	16,526			(6,672		)	24,090			12,569			46,513
	Income (loss) from continuing operations	19,743			(12,584		)	32,196			12,703			52,058
	Income (loss) from discontinued operations, net of income taxes	(5		)	—			—			4			(1		)
	Net income (loss)	19,738			(12,584		)	32,196			12,707			52,057
	Less: net income attributable to noncontrolling interests	6,150			5,025			6,934			4,633			22,817
	Net income (loss) attributable to SemGroup	$	13,588		$	(17,609	)	$	25,262		$	8,074		$	29,240
	Earnings (loss) per share—basic	$	0.32		$	(0.41	)	$	0.59		$	0.19		$	0.69
	Earnings (loss) per share—diluted	$	0.29		$	(0.41	)	$	0.59		$	0.18		$	0.68
	Summarized information on our consolidated results of operations for the quarters during the year ended December 31, 2013 is shown below (in thousands, except per share amounts):
		First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	Total revenues	$	287,696		$	324,244		$	357,748		$	457,328		$	1,427,016
	Loss (gain) on disposal of long-lived assets, net	(162		)	(376		)	408			(109		)	(239		)
	Other operating costs and expenses	282,813			312,103			344,979			448,796			1,388,691
	Total expenses	282,651			311,727			345,387			448,687			1,388,452
	Earnings from equity method investments	17,345			14,861			7,483			12,788			52,477
	Gain on issuance of common units by equity method investee	—			—			—			26,873			26,873
	Operating income	22,390			27,378			19,844			48,302			117,914
	Other expenses, net	27,862			10,613			13,294			17,646			69,415
	Income (loss) from continuing operations before income taxes	(5,472		)	16,765			6,550			30,656			48,499
	Income tax expense (benefit)	(54,006		)	9,288			3,413			24,051			(17,254		)
	Income from continuing operations	48,534			7,477			3,137			6,605			65,753
	Income (loss) from discontinued operations, net of income taxes	32			35			(2		)	(6		)	59
	Net income	48,566			7,512			3,135			6,599			65,812
	Less: net income attributable to noncontrolling interests	5,143			3,943			5,054			3,319			17,710
	Net income (loss) attributable to SemGroup	$	43,423		$	3,569		$	(1,919	)	$	3,280		$	48,102
	Earnings (loss) per share—basic	$	1.03		$	0.08		$	(0.05	)	$	0.08		$	1.14
	Earnings (loss) per share—diluted	$	1.03		$	0.08		$	(0.05	)	$	0.08		$	1.13

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS
	NGL Energy Partners LP and subsidiaries (Gavilon, LLC and High Sierra Crude Oil and Marketing, LLC)
	As described in Note 5, we own interests in NGL Energy, which we account for under the equity method.
	During the years ended December 31, 2014, 2013 and 2012, we generated the following transactions with NGL Energy and its subsidiaries (in thousands):
		Year Ended December 31, 2014		Year Ended December 31, 2013		Year Ended December 31, 2012
	Revenues	$	456,987	$	796,440	$	421,311
	Purchases	$	437,015	$	669,450	$	336,612
	Reimbursements from NGL Energy for services	$	168	$	198	$	575
	White Cliffs
	We generated approximately $2.9 million, $2.9 million and $2.5 million of revenue from services we provided to White Cliffs during the years ended December 31, 2014, 2013 and 2012, respectively. We incurred $3.9 million of cost for the year ended December 31, 2014 related to transportation fees for shipments on White Cliffs.
	Glass Mountain
	We incurred $0.8 million of cost for the year ended December 31, 2014 related to transportation fees for shipments on the Glass Mountain Pipeline. We received $0.7 million in fees from Glass Mountain for the year ended December 31, 2014, respectively, related to support and administrative services associated with pipeline operations.
	Legal Services
	The law firm of Conner & Winters, LLP, of which Mark D. Berman is a partner, performs legal services for us. Mr. Berman is the spouse of Candice L. Cheeseman, General Counsel and Secretary. Mr. Berman does not perform any legal services for us. SemGroup paid $1.3 million, $1.9 million and $1.7 million in legal fees and related expenses to this law firm during the years ended December 31, 2014, 2013 and 2012, respectively (of which $0.1 million, $0.2 million and $0.1 million was paid by White Cliffs, respectively).

Condensed_Consolidating_Guaran

Condensed Consolidating Guarantor Financial Statements	12 Months Ended
	Dec. 31, 2014
Condensed Consolidating Guarantor Financial Statements [Abstract]
Condensed Financial Information of Parent Company Only Disclosure [Text Block]	CONDENSED CONSOLIDATING GUARANTOR FINANCIAL STATEMENTS
	We have outstanding $300 million of 7.50% senior unsecured notes due 2021 (the “Notes”). The Notes are guaranteed by certain of our subsidiaries as follows: SemGas, L.P., SemCanada, L.P., SemCanada II, L.P., SemMaterials, L.P., SemGroup Europe Holding, L.L.C., SemOperating G.P., L.L.C., SemMexico, L.L.C., SemDevelopment, L.L.C., Rose Rock Midstream Holdings, LLC, Wattenberg Holding, LLC, Glass Mountain Holding, LLC and Mid-America Midstream Gas Services, L.L.C. (collectively, the "Guarantors").
	The guarantees of the Notes are full and unconditional and constitute the joint and several obligations of the Guarantors. Each of the Guarantors is 100% owned by SemGroup Corporation (the "Parent"). There are no significant restrictions upon the ability of the Parent or any of the Guarantors to obtain funds from its respective subsidiaries by dividend or loan. None of the assets of the Guarantors represent restricted net assets pursuant to Rule 4-08(e)(3) of Regulation S-X under the Securities Act.
	Condensed consolidating financial statements for the Parent, the Guarantors and non-guarantors as of December 31, 2014 and 2013 and for the years ended December 31, 2014, 2013 and 2012 are presented on an equity method basis in the tables below (in thousands).
	Intercompany receivable and payable balances, including notes receivable and payable, are capital transactions primarily to facilitate the capital needs of our subsidiaries. As such, subsidiary intercompany balances have been reported as a reduction to equity on the condensed consolidating Guarantor balance sheets. The Parent's net intercompany balance, including note receivable, and investments in subsidiaries have been reported in equity method investments on the condensed consolidating Guarantor balance sheets. Intercompany transactions, such as daily cash management activities, have been reported as financing activities within the condensed consolidating Guarantor statements of cash flows. Quarterly cash distributions from Rose Rock representing a return on capital have been included in the Parent's cash flows from operations. Dispositions of the Parent's investments in subsidiaries have been treated as investing activities in the cash flow statement, consistent with the presentation of investments in subsidiaries as equity method investments. These balances are eliminated through consolidating adjustments below.
	Condensed Consolidating Guarantor Balance Sheets
		31-Dec-14
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	ASSETS
	Current assets:
	Cash and cash equivalents	$	9,254		$	—		$	35,486		$	(4,142	)	$	40,598
	Restricted cash	3,856			—			3,124			—			6,980
	Accounts receivable	9,669			32,932			308,733			—			351,334
	Receivable from affiliates	2,512			6,628			15,655			(7,976		)	16,819
	Inventories	—			248			43,284			—			43,532
	Other current assets	10,498			615			8,904			—			20,017
	Total current assets	35,789			40,423			415,186			(12,118		)	479,280
	Property, plant and equipment	4,112			512,508			740,205			—			1,256,825
	Equity method investments	1,551,825			692,872			269,634			(1,936,411		)	577,920
	Goodwill	—			13,052			45,274			—			58,326
	Other intangible assets	26			152,383			20,656			—			173,065
	Other noncurrent assets, net	24,555			958			18,873			—			44,386
	Total assets	$	1,616,307		$	1,412,196		$	1,509,828		$	(1,948,529	)	$	2,589,802
	LIABILITIES AND OWNERS’ EQUITY
	Current liabilities:
	Accounts payable	$	649		$	22,477		$	234,051		$	—		$	257,177
	Payable to affiliates	21			52			21,363			(7,976		)	13,460
	Accrued liabilities	11,989			19,154			61,549			2			92,694
	Payables to pre-petition creditors	3,129			—			—			—			3,129
	Deferred revenue	—			—			23,688			—			23,688
	Other current liabilities	224			707			543			—			1,474
	Current portion of long-term debt	—			—			40			—			40
	Total current liabilities	16,012			42,390			341,234			(7,974		)	391,662
	Long-term debt	335,000			—			490,946			(58,854		)	767,092
	Deferred income taxes	112,897			—			49,059			—			161,956
	Other noncurrent liabilities	2,886			—			46,769			—			49,655
	Commitments and contingencies
	Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	1,149,512			1,369,806			511,891			(1,881,701		)	1,149,508
	Noncontrolling interests in consolidated subsidiaries	—			—			69,929			—			69,929
	Total owners’ equity	1,149,512			1,369,806			581,820			(1,881,701		)	1,219,437
	Total liabilities and owners’ equity	$	1,616,307		$	1,412,196		$	1,509,828		$	(1,948,529	)	$	2,589,802
		31-Dec-13
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	ASSETS
	Current assets:
	Cash and cash equivalents	$	2,545		$	—		$	78,364		$	(1,558	)	$	79,351
	Restricted cash	3,851			—			1,268			—			5,119
	Accounts receivable	649			14,642			308,674			—			323,965
	Receivable from affiliates	1,519			14,063			56,040			(4,349		)	67,273
	Inventories	—			1,046			43,249			—			44,295
	Other current assets	8,712			193			5,106			—			14,011
	Total current assets	17,276			29,944			492,701			(5,907		)	534,014
	Property, plant and equipment	4,114			366,067			735,547			—			1,105,728
	Equity method investments	1,511,922			461,056			159,321			(1,567,175		)	565,124
	Goodwill	—			23,839			38,182			—			62,021
	Other intangible assets	31			163,144			11,663			—			174,838
	Other noncurrent assets, net	15,263			1,302			12,324			—			28,889
	Total assets	$	1,548,606		$	1,045,352		$	1,449,738		$	(1,573,082	)	$	2,470,614
	LIABILITIES AND OWNERS’ EQUITY
	Current liabilities:
	Accounts payable	$	1,172		$	24,234		$	229,061		$	—		$	254,467
	Payable to affiliates	17			115			67,062			(4,915		)	62,279
	Accrued liabilities	10,072			17,341			56,011			5			83,429
	Payables to pre-petition creditors	3,124			—			53			—			3,177
Deferred revenue	—			—			25,538			—			25,538
Other current liabilities	61,875			715			7,697			—			70,287
Current portion of long-term debt	—			—			37			—			37
Total current liabilities	76,260			42,405			385,459			(4,910		)	499,214
Long-term debt	370,000			—			245,088			—			615,088
Deferred income taxes	48,436			—			52,509			—			100,945
Other noncurrent liabilities	8			—			41,496			—			41,504
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	1,053,902			1,002,947			565,225			(1,568,172		)	1,053,902
Noncontrolling interests in consolidated subsidiaries	—			—			159,961			—			159,961
Total owners’ equity	1,053,902			1,002,947			725,186			(1,568,172		)	1,213,863
Total liabilities and owners’ equity	$	1,548,606		$	1,045,352		$	1,449,738		$	(1,573,082	)	$	2,470,614
Condensed Consolidating Guarantor Statements of Operations
	Year Ended December 31, 2014
	Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
Revenues:
Product	$	—		$	338,621		$	1,479,543		$	(37,850	)	$	1,780,314
Service	—			44,592			188,647			—			233,239
Other	—			—			109,026			—			109,026
Total revenues	—			383,213			1,777,216			(37,850		)	2,122,579
Expenses:
Costs of products sold, exclusive of depreciation and amortization shown below	—			273,309			1,387,899			(37,850		)	1,623,358
Operating	—			33,591			213,022			—			246,613
General and administrative	22,394			10,796			54,655			—			87,845
Depreciation and amortization	1,678			29,677			67,042			—			98,397
Loss (gain) loss on disposal or impairment of long-lived assets, net	5,945			54,698			(28,051		)	—			32,592
Total expenses	30,017			402,071			1,694,567			(37,850		)	2,088,805
Earnings from equity method investments	48,760			102,866			49,620			(137,047		)	64,199
Gain on issuance of common units by equity method investee	29,020			—			—			—			29,020
Operating income	47,763			84,008			132,269			(137,047		)	126,993
Other expenses (income):
Interest expense	8,423			19,186			24,740			(3,305		)	49,044
Foreign currency transaction gain	—			—			(86		)	—			(86		)
Other expense (income), net	(24,092		)	500			(246		)	3,302			(20,536		)
Total other expenses (income), net	(15,669		)	19,686			24,408			(3		)	28,422
Income from continuing operations before income taxes	63,432			64,322			107,861			(137,044		)	98,571
Income tax expense	34,192			—			12,321			—			46,513
Income from continuing operations	29,240			64,322			95,540			(137,044		)	52,058
Loss from discontinued operations, net of income taxes	—			—			(1		)	—			(1		)
Net income	29,240			64,322			95,539			(137,044		)	52,057
Less: net income attributable to noncontrolling interests	—			—			22,817			—			22,817
Net income attributable to SemGroup	$	29,240		$	64,322		$	72,722		$	(137,044	)	$	29,240
Net income	$	29,240		$	64,322		$	95,539		$	(137,044	)	$	52,057
Other comprehensive income (loss), net of income taxes	5,159			—			(29,446		)	—			(24,287		)
Comprehensive income	34,399			64,322			66,093			(137,044		)	27,770
Less: comprehensive income attributable to noncontrolling interests	—			—			22,817			—			22,817
Comprehensive income attributable to SemGroup	$	34,399		$	64,322		$	43,276		$	(137,044	)	$	4,953
	Year Ended December 31, 2013
	Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
Revenues:
Product	$	—		$	224,072		$	944,984		$	(23,952	)	$	1,145,104
Service	—			3,868			136,330			—			140,198
Other	—			—			141,714			—			141,714
Total revenues	—			227,940			1,223,028			(23,952		)	1,427,016
Expenses:
Costs of products sold, exclusive of depreciation and amortization shown below	—			166,735			877,317			(23,952		)	1,020,100
Operating	—			19,541			204,044			—			223,585
General and administrative	21,560			9,437			47,600			—			78,597
Depreciation and amortization	2,001			14,452			49,956			—			66,409
Loss (gain) on disposal of long-lived assets, net	—			668			(907		)	—			(239		)
Total expenses	23,561			210,833			1,178,010			(23,952		)	1,388,452
Earnings from equity method investments	67,965			54,995			44,203			(114,686		)	52,477
Gain on issuance of common units by equity method investee	26,873			—			—			—			26,873
Operating income	71,277			72,102			89,221			(114,686		)	117,914
Other expenses (income):
Interest expense	4,826			9,781			15,947			(5,412		)	25,142
Foreign currency transaction gain	—			—			(1,633		)	—			(1,633		)
Other expense (income), net	40,928			—			(434		)	5,412			45,906
Total other expenses, net	45,754			9,781			13,880			—			69,415
Income from continuing operations before income taxes	25,523			62,321			75,341			(114,686		)	48,499
Income tax expense (benefit)	(22,579		)	—			5,325			—			(17,254		)
Income from continuing operations	48,102			62,321			70,016			(114,686		)	65,753
Income (loss) from discontinued operations, net of income taxes	—			65			(6		)	—			59
Net income	48,102			62,386			70,010			(114,686		)	65,812
Less: net income attributable to noncontrolling interests	—			—			17,710			—			17,710
Net income attributable to SemGroup	$	48,102		$	62,386		$	52,300		$	(114,686	)	$	48,102
Net income	$	48,102		$	62,386		$	70,010		$	(114,686	)	$	65,812
Other comprehensive loss, net of income taxes	(1,517		)	—			(38		)	—			(1,555		)
Comprehensive income	46,585			62,386			69,972			(114,686		)	64,257
Less: comprehensive income attributable to noncontrolling interests	—			—			17,710			—			17,710
Comprehensive income attributable to SemGroup	$	46,585		$	62,386		$	52,262		$	(114,686	)	$	46,547
	Year Ended December 31, 2012
	Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
Revenues:
Product	$	—		$	123,424		$	840,892		$	(10,578	)	$	953,738
Service	—			1,198			116,523			—			117,721
Other	—			387			165,651			—			166,038
Total revenues	—			125,009			1,123,066			(10,578		)	1,237,497
Expenses:
Costs of products sold, exclusive of depreciation and amortization shown below	—			98,224			787,239			(10,578		)	874,885
Operating	—			12,719			211,981			—			224,700
General and administrative	22,105			8,360			41,453			—			71,918
Depreciation and amortization	2,496			6,448			39,266			—			48,210
Loss (gain) on disposal of long-lived assets, net	—			276			(3,807		)	—			(3,531		)
Total expenses	24,601			126,027			1,076,132			(10,578		)	1,216,182
Earnings from equity method investments	66,671			85,330			36,439			(152,404		)	36,036
Operating income	42,070			84,312			83,373			(152,404		)	57,351
Other expenses (income):
Interest expense	3,942			(240		)	11,056			(5,856		)	8,902
Foreign currency transaction loss	—			—			298			—			298
Other expense (income), net	15,698			(21		)	(262		)	5,856			21,271
Total other expenses (income), net	19,640			(261		)	11,092			—			30,471
Income from continuing operations before income taxes	22,430			84,573			72,281			(152,404		)	26,880
Income tax (benefit) expense	334			—			(2,412		)	—			(2,078		)
Income from continuing operations	22,096			84,573			74,693			(152,404		)	28,958
Income (loss) from discontinued operations, net of income taxes	4			(17		)	2,952			—			2,939
Net income	22,100			84,556			77,645			(152,404		)	31,897
Less: net income attributable to noncontrolling interests	—			—			9,797			—			9,797
Net income attributable to SemGroup	$	22,100		$	84,556		$	67,848		$	(152,404	)	$	22,100
Net income	$	22,100		$	84,556		$	77,645		$	(152,404	)	$	31,897
Other comprehensive income, net of income taxes	917			—			11,659			—			12,576
Comprehensive income	23,017			84,556			89,304			(152,404		)	44,473
Less: comprehensive income attributable to noncontrolling interests	—			—			9,797			—			9,797
Comprehensive income attributable to SemGroup	$	23,017		$	84,556		$	79,507		$	(152,404	)	$	34,676
Condensed Consolidating Guarantor Statements of Cash Flows
	Year Ended December 31, 2014
	Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
Net cash provided by operating activities	$	27,393		$	56,178		$	188,376		$	(90,289	)	$	181,658
Cash flows from investing activities:
Capital expenditures	(1,672		)	(180,361		)	(88,473		)	—			(270,506		)
Proceeds from sale of long-lived assets	—			2,368			2,077			—			4,445
Contributions to equity method investments	—			(16,201		)	(54,930		)	—			(71,131		)
Payments to acquire businesses	—			(514		)	(43,994		)	—			(44,508		)
Proceeds from sale of common units of equity method investee	79,741			—			—			—			79,741
Proceeds from the sale of interest in SemCrude Pipeline, L.L.C. to Rose Rock Midstream L.P.	114,412			—			—			(114,412		)	—
Distributions in excess of equity in earnings of affiliates	1,843			2,344			9,390			(1,843		)	11,734
Net cash provided by (used in) investing activities	194,324			(192,364		)	(175,930		)	(116,255		)	(290,225		)
Cash flows from financing activities:
Debt issuance costs	(93		)	—			(8,593		)	—			(8,686		)
Borrowings on credit facilities and issuance of senior unsecured notes	405,500			—			848,744			—			1,254,244
Principal payments on credit facilities and other obligations	(440,500		)	—			(661,772		)	—			(1,102,272		)
Distributions to noncontrolling interests	—			—			(28,494		)	—			(28,494		)
Proceeds from warrant exercises	1,451			—			—			—			1,451
Repurchase of common stock for payment of statutory taxes due on equity-based compensation	(719		)	—			—			—			(719		)
Dividends paid	(44,206		)	—			—			—			(44,206		)
Proceeds from issuance of common stock under employee stock purchase plan	340			—			—			—			340
Excess tax benefit from equity-based awards	1,650			—			—			—			1,650
Intercompany borrowings (advances), net	(138,431		)	136,186			(201,715		)	203,960			—
Net cash provided by (used in) financing activities	(215,008		)	136,186			(51,830		)	203,960			73,308
Effect of exchange rate changes on cash and cash equivalents	—			—			(3,494		)	—			(3,494		)
Change in cash and cash equivalents	6,709			—			(42,878		)	(2,584		)	(38,753		)
Cash and cash equivalents at beginning of period	2,545			—			78,364			(1,558		)	79,351
Cash and cash equivalents at end of period	$	9,254		$	—		$	35,486		$	(4,142	)	$	40,598
	Year Ended December 31, 2013
	Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
Net cash provided by (used in) operating activities	$	20,130		$	24,642		$	148,872		$	(20,235	)	$	173,409
Cash flows from investing activities:
Capital expenditures	(734		)	(123,246		)	(91,629		)	—			(215,609		)
Proceeds from sale of long-lived assets	23			19			1,237			—			1,279
Contributions to equity method investments	(18,775		)	(57,850		)	(97,243		)	—			(173,868		)
Payments to acquire businesses	—			(313,487		)	(48,969		)	—			(362,456		)
Proceeds from the sale of interest in SemCrude Pipeline, L.L.C. to Rose Rock Midstream, L.P.	362,600			—			—			(362,600		)	—
Distributions in excess of equity in earnings of affiliates	—			—			12,246			—			12,246
Net cash provided by (used in) investing activities	343,114			(494,564		)	(224,358		)	(362,600		)	(738,408		)
Cash flows from financing activities:
Debt issuance costs	(10,866		)	—			(4,070		)	—			(14,936		)
Borrowings on debt	706,000			—			562,474			—			1,268,474
Principal payments on debt and other obligations	(537,500		)	—			(321,912		)	—			(859,412		)
Proceeds from issuance of Rose Rock Midstream, L.P. common units, net of offering costs	—			—			210,226			—			210,226
Distributions to noncontrolling interests	—			—			(17,647		)	—			(17,647		)
Proceeds from warrant exercises	225			—			—			—			225
Repurchase of common stock	(371		)	—			—			—			(371		)
Dividends paid	(25,429		)	—			—			—			(25,429		)
Intercompany borrowings (advances), net	(511,881		)	469,922			(342,256		)	384,215			—
Net cash provided by (used in) financing activities	(379,822		)	469,922			86,815			384,215			561,130
Effect of exchange rate changes on cash and cash equivalents	—			—			3,191			—			3,191
Change in cash and cash equivalents	(16,578		)	—			14,520			1,380			(678		)
Cash and cash equivalents at beginning of period	19,123			—			63,844			(2,938		)	80,029
Cash and cash equivalents at end of period	$	2,545		$	—		$	78,364		$	(1,558	)	$	79,351
	Year Ended December 31, 2012
	Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
Net cash provided by (used in) operating activities	$	(4,535	)	$	6,236		$	93,534		$	(15,593	)	$	79,642
Cash flows from investing activities:
Capital expenditures	(1,977		)	(59,317		)	(58,025		)	—			(119,319		)
Proceeds from sale of long-lived assets	19			(202		)	2,824			—			2,641
Contributions to equity method investments	(1,740		)	(74,434		)	(2,079		)	—			(78,253		)
Proceeds from the sale of non-consolidated affiliate	—			—			3,500			—			3,500
Proceeds from the sale of SemStream assets	12,250			—			—			—			12,250
Distributions in excess of equity in earnings of affiliates	9,218			—			8,072			—			17,290
Net cash provided by (used in) investing activities	17,770			(133,953		)	(45,708		)	—			(161,891		)
Cash flows from financing activities:
Debt issuance costs	(455		)	—			(252		)	—			(707		)
Borrowings on credit facilities	318,000			—			—			—			318,000
Principal payments on credit facilities and other obligations	(194,000		)	—			(28,066		)	—			(222,066		)
Distributions to noncontrolling interests	—			—			(8,502		)	—			(8,502		)
Repurchase of common stock	(242		)	—			—			—			(242		)
Intercompany borrowings (advances), net	(117,526		)	127,717			(25,608		)	15,417			—
Net cash provided by (used in) financing activities	5,777			127,717			(62,428		)	15,417			86,483
Effect of exchange rate changes on cash and cash equivalents	—			—			(610		)	—			(610		)
Change in cash and cash equivalents	19,012			—			(15,212		)	(176		)	3,624
Change in cash and cash equivalents included in discontinued operations	—			—			2,792			—			2,792
Change in cash and cash equivalents from continuing operations	19,012			—			(12,420		)	(176		)	6,416
Cash and cash equivalents at beginning of period	111			—			76,264			(2,762		)	73,613
Cash and cash equivalents at end of period	$	19,123		$	—		$	63,844		$	(2,938	)	$	80,029

Recovered_Sheet1

Consolidation and Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2014
Consolidation and Basis of Presentation [Abstract]
Consolidation, Policy [Policy Text Block]	The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States.
	Consolidated subsidiaries
	Our consolidated financial statements include the accounts of our controlled subsidiaries, including Rose Rock. All significant transactions between our consolidated subsidiaries have been eliminated. Outside ownership interests in consolidated subsidiaries are reported as noncontrolling interests in the consolidated financial statements.
	Proportionally consolidated assets
	Our SemCAMS segment owns undivided interests in certain natural gas gathering and processing assets, for which we record only our proportionate share of the assets on the consolidated balance sheets. The net book value of the property, plant and equipment recorded by us associated with these undivided interests is approximately $209.8 million at December 31, 2014. We serve as operator of these facilities and incur the costs of operating the facilities (recorded as operating expenses in the consolidated statements of operations) and charge the other owners for their proportionate share of the costs (recorded as other revenue in the consolidated statements of operations).

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Use of Estimates	USE OF ESTIMATES—The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts and disclosures in the financial statements. Our significant estimates include, but are not limited to: (1) allowances for doubtful accounts receivable; (2) estimated useful lives of assets, which impact depreciation; (3) estimated fair values of long-lived assets used in impairment tests; (4) fair values of derivative instruments; (5) valuation allowances for deferred tax assets; and (6) accrual and disclosure of contingent losses. Although management believes these estimates are reasonable, actual results could differ materially from these estimates.
Cash And Cash Equivalents	CASH AND CASH EQUIVALENTS—Cash includes currency on hand and demand and time deposits with banks or other financial institutions. Cash equivalents include highly liquid investments with maturities of three months or less at the date of purchase. Balances at financial institutions may exceed federally insured limits.
Restricted Cash	RESTRICTED CASH—At December 31, 2014, we had not yet completed the process of disbursing funds held in reserve accounts to settle pre-petition claims related to our predecessor's bankruptcy. Of the restricted cash balance of $7.0 million at December 31, 2014, approximately $3.8 million is restricted for this purpose. See payables to pre-petition creditors below.
Accounts Receivable	ACCOUNTS RECEIVABLE—Accounts receivable are reported net of the allowance for doubtful accounts. Our assessment of the allowance for doubtful accounts is based on several factors, including the overall creditworthiness of our customers, existing economic conditions, and the amount and age of past due accounts. We enter into netting arrangements with certain counterparties to help mitigate credit risk. Receivables subject to netting are presented as gross receivables (with the related accounts payable also presented gross) until such time as the balances are settled. Receivables are considered past due if full payment is not received by the contractual due date. Past due accounts are written off against the allowance for doubtful accounts only after all collection attempts have been exhausted.
Inventories	INVENTORIES—Inventories primarily consist of natural gas and natural gas liquids, crude oil, and asphalt. Inventories are valued at the lower of cost or market, with cost generally determined using the weighted-average method. The cost of inventory includes applicable transportation costs.
	We enter into exchanges with third parties whereby we acquire products that differ in location, grade, or delivery date from products we have available for sale. These exchanges are valued at cost, and although a transportation, location or product differential may be recorded, generally no gain or loss is recognized.
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENT—Property, plant and equipment is recorded at cost. We capitalize costs that extend or increase the future economic benefits of property, plant and equipment, and expense maintenance costs that do not. When assets are disposed of, their cost and related accumulated depreciation are removed from the balance sheet, and any resulting gain or loss is recorded as a gain or loss on disposal or impairment of long-lived assets in the consolidated statements of operations.
	Our SemCAMS segment operates plants which periodically undergo planned major maintenance activities, typically occurring every four to five years.  Planned major maintenance projects that do not increase the overall life or capacity of the related assets are recorded in operating expense as incurred, whereas major maintenance activity costs that materially increase the life or capacity of the underlying assets are capitalized. When maintenance expenses are recoverable from the producers who use the plants, they are recorded as revenue, and typically include a 10% overhead fee.
	Depreciation is calculated primarily on the straight-line method over the following estimated useful lives:
	Pipelines and related facilities	10 – 31 years
	Storage and terminal facilities	10 – 25 years
	Natural gas gathering and processing facilities	10 – 31 years
	Trucking equipment and other	3 – 7 years
	Office property and equipment	3 – 31 years
	Construction in process is reclassified to the fixed asset categories above and depreciation commences once the asset has been placed in-service.
Linefill	LINEFILL—Pipelines and storage facilities generally require a minimum volume of product in the system to enable the system to operate. Such product, known as linefill, is generally not available to be withdrawn from the system. Linefill owned by us in facilities operated by us is recorded at historical cost, is included in property, plant and equipment in the consolidated balance sheets, and is not depreciated. We also own linefill in third-party facilities, which is included in inventory on the consolidated balance sheets.
Impairment of Long-Lived Assets	IMPAIRMENT OF LONG-LIVED ASSETS—We test long-lived asset groups for impairment when events or circumstances indicate that the net book value of the asset group may not be recoverable. We test an asset group for impairment by estimating the undiscounted cash flows expected to result from its use and eventual disposition. If the estimated undiscounted cash flows are lower than the net book value of the asset group, we then estimate the fair value of the asset group and record a reduction to the net book value of the assets and a corresponding impairment loss.
Goodwill	GOODWILL—We test goodwill for impairment on an annual basis, or more often if circumstances warrant, by estimating the fair value of the asset group to which the goodwill relates and comparing this fair value to the net book value of the asset group. If fair value is less than net book value, we estimate the implied fair value of goodwill, reduce the book value of the goodwill to the implied fair value, and record a corresponding impairment loss. Our policy is to test goodwill for impairment on October 1 of each year.
Intangible Assets	INTANGIBLE ASSETS—Intangible assets are stated at cost, net of accumulated amortization, which is recorded on a straight-line or accelerated basis over the life of the asset. We review amortizable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. If such a review should indicate that the carrying amount of amortizable intangible assets is not recoverable, we reduce the carrying amount of such assets to fair value.
Equity Method Investments	EQUITY METHOD INVESTMENTS—We account for an investment under the equity method when we have significant influence over, but not control of, the significant operating decisions of the investee. Under the equity method, we record in the consolidated statements of operations our share of the earnings or losses of the investee, with a corresponding adjustment to the investment balance on our consolidated balance sheet. When we receive a distribution from an equity method investee, we record a corresponding reduction to the investment balance. When an equity method investee issues additional ownership interests which dilute our ownership interest, we recognize a gain or loss in our consolidated statements of operations.
	For equity method investments for which we do not expect financial information to be consistently available on a timely basis to apply the equity method currently, our policy is to apply the equity method consistently on a one-quarter lag.
Debt Issuance Costs	DEBT ISSUANCE COSTS—Costs incurred in connection with the issuance of long-term debt are reported as other noncurrent assets and are amortized to interest expense using the straight-line method over the term of the related debt. Use of the straight-line method of amortization does not differ materially from the “effective interest” method.
Commodity Derivative Instruments	COMMODITY DERIVATIVE INSTRUMENTS—We generally record the fair value of commodity derivative instruments on the consolidated balance sheets and the change in fair value as an increase or decrease to product revenue.
	As shown in Note 14, the fair value of commodity derivatives at December 31, 2014 and 2013 are recorded to other current assets or other current liabilities on the consolidated balance sheets. Related margin deposits are recorded to other current assets or other current liabilities on the consolidated balance sheets. Margin deposits are not generally netted against derivative assets or liabilities.
	The fair value of a derivative contract is determined based on the nature of the transaction and the market in which the transaction was executed. Quoted market prices, when available, are used to value derivative transactions. In situations where quoted market prices are not readily available, we estimate the fair value using other valuation techniques that reflect the best information available under the circumstances. Fair value measurements of derivative assets include consideration of counterparty credit risk. Fair value measurements of derivative liabilities include consideration of our creditworthiness.
	We have elected “normal purchase” and “normal sale” treatment for certain commitments to purchase or sell petroleum products at future dates. This election is only available when a transaction that would ordinarily meet the definition of a derivative but instead is expected to result in physical delivery of product over a reasonable period in the normal course of business and is not expected to be net settled. Agreements accounted for under this election are not recorded at fair value; instead, the transaction is recorded when the product is delivered.
Payables to Pre-Petition Creditors	PAYABLES TO PRE-PETITION CREDITORS—At December 31, 2014, we had not yet completed the process of disbursing funds held in reserve accounts to settle pre-petition claims related to our predecessor's bankruptcy. We recorded a liability of $3.1 million at December 31, 2014 associated with these obligations and a liability of $0.7 million which is associated with discontinued operations and is reported within other current liabilities. Cash is held in accounts restricted for this purpose which is included in Restricted Cash on the balance sheet. All pre-petition claims payable from these accounts have been settled and we expect to disburse the cash as soon as the accounts have been reconciled.
Contingent Losses	CONTINGENT LOSSES—We record a liability for a contingent loss when it is probable that a loss has been incurred and the amount of the loss can be reasonably estimated. We record attorneys’ fees incurred in connection with a contingent loss at the time the fees are incurred. We do not record liabilities for attorneys’ fees that are expected to be incurred in the future.
Asset Retirement Obligations	ASSET RETIREMENT OBLIGATIONS—Asset retirement obligations include legal or contractual obligations associated with the retirement of long-lived assets, such as requirements to incur costs to dispose of equipment or to remediate the environmental impacts of the normal operation of the assets. We record liabilities for asset retirement obligations when a known obligation exists under current law or contract and when a reasonable estimate of the value of the liability can be made.
Discontinued Operations	DISCONTINUED OPERATIONS—We classify a component of our business as a discontinued operation when we commit to a plan to sell the component and believe it is probable that a sale will be completed within one year. A component that is disposed of in a manner other than by sale is classified as discontinued when the component is actually disposed. Investments accounted for under the equity method, or the cost method, do not qualify for treatment as discontinued operations. A component that is disposed of may not qualify for treatment as a discontinued operation if we have significant continuing involvement in the operations of the component after the disposal.
	Once a component meets the requirements to be classified as a discontinued operation, previous financial statements are retrospectively adjusted to reflect the component as a discontinued operation for all periods presented. Income and losses of discontinued operations (excluding corporate general and administrative expense allocations) are combined into one line on the consolidated statements of operations. The cash flows from discontinued operations are not separately identified in the consolidated statements of cash flows.
	In April 2014, the FASB issued ASU 2014-08, "Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity," which raises the threshold for a disposal to qualify as a discontinued operation and requires new disclosures of both discontinued operations and certain other disposals that do not meet the definition of a discontinued operation. For public entities, this ASU is effective for fiscal years beginning on or after December 15, 2014, and interim periods within those years. The Company will adopt this guidance in the first quarter of 2015. The impact is not expected to be material.
Revenue Recognition	REVENUE RECOGNITION—Sales of product, as well as gathering and marketing revenues, are recognized at the time title to the product transfers to the purchaser, which typically occurs upon receipt of the product by the purchaser. Terminal and storage revenues are recognized at the time the service is performed. Revenue for the transportation of product is recognized upon delivery of the product to its destination. Certain revenue transactions are reported on a net basis, including derivative instruments considered held for trading purposes and certain buy/sell transactions (see “Purchases and Sales of Inventory with the Same Counterparty”). Other revenue primarily represents operating cost recovery from working interest owners in certain processing plants and is recorded when earned in accordance with the terms of related agreements. Taxes collected from customers and remitted to governmental authorities are recorded on a net basis (excluded from revenue).
	In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers", which supersedes nearly all existing revenue recognition guidance under U.S. GAAP. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration to which an entity expects to be entitled for those goods or services. ASU 2014-09 defines a five step process to achieve this core principle and, in doing so, more judgment and estimates may be required within the revenue recognition process than are required under existing U.S. GAAP.
	The standard is effective for annual periods beginning after December 15, 2016, and interim periods therein, using either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (ii) a retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures). We are currently evaluating the impact of our pending adoption of ASU 2014-09 on our consolidated financial statements and have not yet determined the method by which we will adopt the standard in 2017.
Costs of Products Sold	COSTS OF PRODUCTS SOLD—Costs of products sold consists of the cost to purchase the product, the cost to transport the product to the point of sale, and the cost to store the product until it is sold.
Purchases and Sales of Inventory With the Same Counterparty	PURCHASES AND SALES OF INVENTORY WITH THE SAME COUNTERPARTY—We routinely enter into transactions to purchase inventory from, and sell inventory to, the same counterparty. Such transactions that are entered into in contemplation of one another are recorded on a net basis.
Currency Translation	CURRENCY TRANSLATION—The consolidated financial statements are presented in U.S. dollars. Our segments operate in four countries, and each segment has identified a “functional currency,” which is the primary currency in the environment in which the segment operates. The functional currencies include the U.S. dollar, the Canadian dollar, the British pound sterling, and the Mexican peso.
	At the end of each reporting period, the assets and liabilities of each segment are translated from its functional currency to U.S. dollars using the exchange rate at the end of the month. The monthly results of operations of each segment are generally translated from its functional currency to U.S. dollars using the average exchange rate during the month. Changes in exchange rates result in currency translation gains and losses, which are recorded within other comprehensive income (loss).
	Certain segments also enter into transactions in currencies other than their functional currencies. At the end of each reporting period, each segment re-measures the related receivables, payables, and cash to its functional currency using the exchange rate at the end of the period. Changes in exchange rates between the time the transactions were entered into and the end of the reporting period result in currency transaction gains or losses, which are recorded in the consolidated statements of operations.
Income Taxes	INCOME TAXES—Deferred income taxes are accounted for under the liability method, which takes into account the differences between the basis of the assets and liabilities for financial reporting purposes and amounts recognized for income tax purposes. We record valuation allowances on deferred tax assets when, in the opinion of management, it is more likely than not that the asset will not be recovered.
	We monitor uncertain tax positions and we recognize tax benefits only when management believes the relevant tax positions would more likely than not be sustained upon examination. We record any interest and any penalties related to income taxes within income tax expense in the consolidated statements of operations.
	In July 2013, the FASB issued ASU 2013-11, "Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists," which requires an unrecognized tax benefit to be classified as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except in certain circumstances. For public entities, this ASU is effective for fiscal years beginning on or after December 15, 2013, and interim periods within those years. The Company adopted this guidance in the first quarter of 2014. The impact was not material.
Reclassifications	RECLASSIFICATIONS—Certain reclassifications have been made to conform prior year balances to the current year presentation.
Pension Benefits	PENSION BENEFITS—Pension cost and obligations are actuarially determined and are affected by assumptions including expected return on plan assets, discount rates, compensation increases, and employee turnover rates. We evaluate our assumptions periodically and make adjustments to these assumptions and the recorded liability as necessary. Actuarial gains or losses are amortized on a straight-line basis over the expected remaining service life of employees in the pension plan.
Equity-Based Compensation	EQUITY-BASED COMPENSATION—We grant certain of our employees equity-based compensation awards which vest contingent on continued service of the recipient and, in some cases, on their achievement of specific performance targets. We record compensation expense for these outstanding awards over applicable service or performance periods based on their grant date fair value with a corresponding increase to additional paid-in capital. The expense to be recorded over the life of the awards is discounted for expected forfeitures during the vesting period.
Noncontrolling interests in consolidated subsidiaries	NONCONTROLLING INTERESTS IN CONSOLIDATED SUBSIDIARIES—Noncontrolling interests represents third-party limited partner unitholders' interests in our consolidated subsidiary, Rose Rock. Rose Rock allocates net income to its limited partners based on the distributions pertaining to the current period's available cash as defined by Rose Rock's partnership agreement. After adjusting for the appropriate period's distributions, the remaining undistributed earnings or excess distributions over earnings, if any, are allocated to Rose Rock's general partner, limited partners and participating securities in accordance with the contractual terms of Rose Rock's partnership agreement and as further prescribed under the two-class method. Incentive distribution rights do not participate in undistributed earnings.
Comprehensive Income	COMPREHENSIVE INCOME (LOSS) AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)—Comprehensive income (loss) is defined as a change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources and includes all changes in equity during a period except those resulting from investments by owners and distributions to owners. Our comprehensive income (loss) consists of currency translation adjustments, changes in the funded status of pension benefit plans and changes in the fair value of interest rate swaps.
	On March 4, 2013, the FASB issued ASU 2013-05, "Parent's Accounting for the Cumulative Translation Adjustment Upon Derecognition of Certain Subsidiaries or Groups of Assets Within a Foreign Entity or of an Investment in a Foreign Entity - a consensus of the FASB Emerging Issues Task Force”, which indicates that the entire amount of a cumulative translation adjustment ("CTA") related to an entity's investment in a foreign entity should be released when there has been a:
	•	sale of a subsidiary or group of net assets within a foreign entity and the sale represents the substantially complete liquidation of the investment in the foreign entity;
	•	loss of a controlling financial interest in an investment in a foreign entity (i.e., the foreign entity is deconsolidated); or
	•	step acquisition for a foreign entity (i.e., when an entity has changed from applying the equity method for an investment in a foreign entity to consolidating the foreign entity).
	The ASU does not change the requirement to release a pro rata portion of the CTA of the foreign entity into earnings for a partial sale of an equity method investment in a foreign entity. For public entities, this ASU is effective for fiscal years beginning on or after December 15, 2013, and interim periods within those years. The Company adopted this guidance in the first quarter of 2014. The impact was not material.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives of Property, Plant and Equipment	Depreciation is calculated primarily on the straight-line method over the following estimated useful lives:
	Pipelines and related facilities	10 – 31 years
	Storage and terminal facilities	10 – 25 years
	Natural gas gathering and processing facilities	10 – 31 years
	Trucking equipment and other	3 – 7 years
	Office property and equipment	3 – 31 years

Rose_Rock_Midstream_LP_Tables

Rose Rock Midstream, L.P. (Tables)	12 Months Ended
	Dec. 31, 2014
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]
Quarterly Target Distributions	Rose Rock’s partnership agreement requires Rose Rock to distribute all of its available cash each quarter in the following manner:
		Total Quarterly Distributions												Marginal Percentage
		Per Unit Target Amount												Interest in Distributions
														Unitholders			General			Incentive
																	Partner			Distribution
																				Rights
	Minimum Quarterly Distributions									$	0.3625			98	%		2	%		—
	First Target Distribution	above		$	0.3625			up to		$	0.416875			98	%		2	%		—
	Second Target Distribution	above		$	0.416875			up to		$	0.453125			85	%		2	%		13	%
	Third Target Distribution	above		$	0.453125			up to		$	0.54375			75	%		2	%		23	%
	Thereafter							above		$	0.54375			50	%		2	%		48	%
Distributions Paid	The following table shows the distributions paid related to the earnings for each of the following periods (in thousands, except for per unit amounts):
		Distribution				Distributions Paid
	Quarter Ended	Per Unit				SemGroup												Noncontrolling			Total
																		Interest			Distributions
						General			Incentive			Common			Subordinated			Common Units
						Partner			Distributions			Units			Units
	December 31, 2011	$	0.067		*	$	23		$	—		$	93		$	561		$	470		$	1,147
	March 31, 2012	$	0.3725			$	128		$	—		$	517		$	3,125		$	2,607		$	6,377
	June 30, 2012	$	0.3825			$	131		$	—		$	532		$	3,209		$	2,678		$	6,550
	September 30, 2012	$	0.3925			$	134		$	—		$	545		$	3,294		$	2,748		$	6,721
	December 31, 2012	$	0.4025			$	167		$	—		$	1,163		$	3,377		$	3,624		$	8,331
	March 31, 2013	$	0.43			$	179		$	41		$	1,242		$	3,607		$	3,872		$	8,941
	June 30, 2013	$	0.44			$	183		$	72		$	1,271		$	3,692		$	3,962		$	9,180
	September 30, 2013	$	0.45			$	232		$	127		$	1,301		$	3,775		$	6,189		$	11,624
	December 31, 2013	$	0.465			$	257		$	244		$	2,041		$	3,901		$	6,398		$	12,841
	31-Mar-14	$	0.495			$	278		$	488		$	2,173		$	4,153		$	6,811		$	13,903
	30-Jun-14	$	0.535			$	334		$	888		$	3,646		$	4,488		$	7,362		$	16,718
	30-Sep-14	$	0.575			$	377		$	1,835		$	3,918		$	4,824		$	7,912		$	18,866
	31-Dec-14	$	0.62		**	$	485		$	3,487		$	6,551		$	5,202		$	8,544		$	24,269
	*Minimum quarterly distribution for quarter ended December 31, 2011 was prorated for the period beginning immediately after the closing of Rose Rock’s IPO, December 14, 2011 through December 31, 2011.
	** The distribution to common unitholders related to earnings for the quarter ended December 31, 2014 was payable on February 13, 2015 to holders of record at February 3, 2015. As such, the Class A units, which converted to common units on January 1, 2015, were eligible for the distribution which is reflected in the amount paid to common unitholders.
Summarized Balance Sheet Information	Certain summarized balance sheet information of Rose Rock is shown below (in thousands):
		31-Dec-14				31-Dec-13
	Cash	$	3,666			$	15,459
	Other current assets	270,224				306,128
	Property, plant and equipment, net	335,910				311,616
	Equity method investment	269,635				224,095
	Goodwill	36,116				28,322
	Other noncurrent assets	29,677				11,627
	Total assets	$	945,228			$	897,247
	Current liabilities	$	263,680			$	293,031
	Long-term debt	432,092				245,088
	Partners’ capital attributable to SemGroup	179,527				120,610
	Partners’ capital attributable to noncontrolling interests	69,929				159,961
	Noncontrolling interest in consolidated subsidiaries retained by SemGroup	—				78,557
	Total liabilities and partners’ capital	$	945,228			$	897,247
Summarized Income Statement Information	Certain summarized income statement information of Rose Rock for the years ended December 31, 2014, 2013, and 2012 is shown below (in thousands):
		Year Ended December 31, 2014				Year Ended December 31, 2013				Year Ended December 31, 2012
	Revenue	$	1,290,644			$	766,526			$	620,417
	Costs of products sold	$	1,131,362			$	663,759			$	546,966
	Operating, general and administrative expenses	$	97,575			$	51,082			$	35,385
	Depreciation and amortization expense	$	36,072			$	23,165			$	12,131
	Earnings from equity method investment	$	57,378			$	17,571			$	—
	Net income	$	62,577			$	38,005			$	23,954
	Noncontrolling interest in consolidated subsidiaries retained by SemGroup	$	7,758			$	1,256			$	—
	Net income attributable to Rose Rock Midstream, L.P.	$	54,819			$	36,749			$	23,954

Equity_Method_Investments_Tabl

Equity Method Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Equity Method Investments [Table Text Block]	Our equity method investments consist of the following (in thousands):
		December 31, 2014		December 31, 2013
	White Cliffs	$	269,635	$	224,095
	NGL Energy	162,246		208,848
	Glass Mountain	146,039		132,181
	Total equity method investments	$	577,920	$	565,124
Cash distributions received from equity method investments [Table Text Block]	Cash distributions received from equity method investments consist of the following (in thousands):
		Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012
	White Cliffs	$	66,768	$	57,576		$	44,514
	NGL Energy	23,404		18,321			9,217
	Glass Mountain	6,823		—			—
	Total cash distributions received from equity method investments	$	96,995	$	75,897		$	53,731
Earnings from Equity Method Investments [Table Text Block]	Our earnings from equity method investments consist of the following (in thousands):
		Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012
	White Cliffs	$	57,378	$	45,459		$	36,439
	NGL Energy*	2,343		7,123			(403		)
	Glass Mountain	4,478		(105		)	—
	Total earnings from equity method investments	$	64,199	$	52,477		$	36,036
	* Excluding gains on issuance of common units of $29.0 million and $26.9 million for the years ended December 31, 2014 and 2013, respectively.
White Cliffs Pipeline, LLC [Member]
Schedule of Balance Sheet Information on Equity Method Investments	Certain summarized balance sheet information of White Cliffs is shown below (in thousands):
		December 31,		December 31,
		2014		2013
	Current assets	$	35,623	$	98,457
	Property, plant and equipment, net	471,179		312,831
	Goodwill	17,000		17,000
	Other intangible assets, net	16,043		20,802
	Total assets	$	539,845	$	449,090
	Current liabilities	$	11,108	$	9,648
	Members’ equity	528,737		439,442
	Total liabilities and members’ equity	$	539,845	$	449,090
Schedule of Income Statement Information on Equity Method Investments	Certain summarized income statement information of White Cliffs for the years ended December 31, 2014, 2013 and 2012 is shown below (in thousands):
		Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012
	Revenue	$	160,369	$	133,310		$	108,125
	Operating, general and administrative expenses	$	23,067	$	23,825		$	14,821
	Depreciation and amortization expense	$	23,257	$	18,668		$	19,963
	Net income	$	114,045	$	90,817		$	73,341
Ngl Energy Partners Lp [Member]
Schedule of Balance Sheet Information on Equity Method Investments	Certain unaudited summarized balance sheet information of NGL Energy is shown below (in thousands):
		(unaudited)		(unaudited)
		September 30,		September 30,
		2014		2013
	Current assets	$	2,585,053	$	1,013,859
	Property plant and equipment, net	1,433,313		631,663
	Goodwill	1,170,490		840,287
	Intangible and other assets, net	1,362,823		540,684
	Total assets	$	6,551,679	$	3,026,493
	Current liabilities	$	1,759,980	$	800,658
	Long-term debt	2,437,351		906,066
	Other noncurrent liabilities	39,518		2,673
	Equity	2,314,830		1,317,096
	Total liabilities and equity	$	6,551,679	$	3,026,493
Schedule of Income Statement Information on Equity Method Investments	Certain unaudited summarized income statement information of NGL Energy for the twelve months ended September 30, 2014 and 2013 is shown below (in thousands):
		(unaudited)		(unaudited)			(unaudited)
		Twelve Months Ended		Twelve Months			Twelve Months
		September 30,		Ended			Ended
		2014		September 30,			September 30,
				2013			2012
	Revenue	$	15,748,520	$	5,935,715		$	2,371,524
	Costs of products sold	$	15,054,291	$	5,478,361		$	2,182,263
	Operating, general and administrative expenses	$	440,609	$	276,905		$	125,889
	Depreciation and amortization expense	$	162,443	$	94,050		$	34,621
	Net income	$	11,409	$	44,378		$	5,405
Glass Mountain Pipeline LLC [Member]
Schedule of Balance Sheet Information on Equity Method Investments	Certain summarized balance sheet information of Glass Mountain is shown below (in thousands):
		December 31,
		2014
	Current assets	$	8,810
	Property, plant and equipment, net	215,876
	Total assets	$	224,686
	Current liabilities	$	2,643
	Other Liabilities	42
	Members’ equity	222,001
	Total liabilities and members’ equity	$	224,686
Schedule of Income Statement Information on Equity Method Investments	Certain unaudited summarized income statement information of Glass Mountain for the year ended December 31, 2014 is shown below (in thousands):
		Year Ended December 31, 2014
	Revenue	$	30,398
	Operating, general and administrative expenses	$	7,176
	Depreciation and amortization expense	$	13,872
	Net income	$	9,344

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2014
Chesapeake crude oil trucking assets [Member]
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	We have recorded the fair value of the assets acquired as follows (in thousands):
	Property, plant and equipment	$	19,092
	Customer contract intangible	17,010
	Goodwill	7,892
	Total assets acquired	$	43,994
Mid-America Midstream Gas Services, LLC [Member]
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	We have recorded the fair value of the assets acquired as follows (in thousands):
	Property, plant and equipment	$	136,949
	Customer contract intangible	164,000
	Goodwill	13,052
	Total assets acquired	$	314,001
Barcas Field Services, LLC [Member]
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	We have recorded the following acquisition date fair values for the assets acquired (in thousands):
	Property, plant and equipment	$	13,865
	Customer contract intangible	6,880
	Goodwill	28,234
	Total assets acquired	$	48,979

Disposals_of_LongLived_Assets_

Disposals of Long-Lived Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Disposals And Impairments Of Long-Lived Assets [Abstract]
Gains (Losses) Related to Disposal or Impairment of Long-Lived Assets	Gains (losses) recorded during the year ended December 31, 2012 related to the disposal of long-lived assets including the following (in thousands):
	Event	Segment	Pre-Tax Gain
	White Cliffs settlement (a)	Crude	$	3,500
	Sale of SemStream residential division assets and liabilities (b)	SemStream	$	3,090

Discontinued_Operations_Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Summarized Information on Results of Discontinued Operations	Certain summarized information on the results of discontinued operations is shown below (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013		Year Ended December 31, 2012
	External revenue	$	—		$	—	$	13,518
	Gain on disposal of long-lived assets, net	$	—		$	—	$	3,090
	Income (loss) from discontinued operations before income taxes	$	(1	)	$	59	$	2,935
	Income tax benefit	—			—		(4		)
	Income (loss) from discontinued operations, net of income taxes	$	(1	)	$	59	$	2,939

Segments_Tables

Segments (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Schedule of Segment Reporting Information
		Year Ended December 31, 2014
		Crude			SemStream			SemCAMS			SemGas			SemLogistics			SemMexico			Corporate			Consolidated
																				and
																				Other
		(in thousands)
	Revenues:
	External	$	1,300,050		$	—		$	176,724		$	342,286		$	12,650		$	290,869		$	—		$	2,122,579
	Intersegment	—			—			—			37,897			—			—			(37,897		)	—
	Total revenues	1,300,050			—			176,724			380,183			12,650			290,869			(37,897		)	2,122,579
	Expenses:
	Costs of products sold, exclusive of depreciation and amortization shown below	1,131,362			—			344			276,852			615			252,082			(37,897		)	1,623,358
	Operating	80,793			—			114,587			32,296			8,361			10,576			—			246,613
	General and administrative	20,351			83			17,417			9,228			6,139			12,125			22,502			87,845
	Depreciation and amortization	40,035			—			14,295			26,353			10,005			6,031			1,678			98,397
	Loss (gain) on disposal or impairment of long-lived assets, net	319			—			(950		)	20,092			(2,490		)	(53		)	15,674			32,592
	Total expenses	1,272,860			83			145,693			364,821			22,630			280,761			1,957			2,088,805
	Earnings from equity method investments	61,856			2,343			—			—			—			—			—			64,199
	Gain on issuance of common units by equity method investee	—			29,020			—			—			—			—			—			29,020
	Operating income (loss)	89,046			31,280			31,031			15,362			(9,980		)	10,108			(39,854		)	126,993
	Other expenses (income), net
	Interest expense (income)	31,072			(5,140		)	13,558			8,570			1,528			166			(710		)	49,044
	Other expense (income), net	479			(34,212		)	20			—			796			(11		)	12,306			(20,622		)
	Total other expenses (income)	31,551			(39,352		)	13,578			8,570			2,324			155			11,596			28,422
	Income (loss) from continuing operations before income taxes	$	57,495		$	70,632		$	17,453		$	6,792		$	(12,304	)	$	9,953		$	(51,450	)	$	98,571
	Additions to long-lived assets	$	127,335		$	—		$	35,286		$	166,207		$	2,974		$	9,690		$	1,672		$	343,164
	Total assets at December 31, 2014 (excluding intersegment receivables)	$	1,158,639		$	162,246		$	279,191		$	662,223		$	150,498		$	107,225		$	69,780		$	2,589,802
	Equity investments at December 31, 2014	$	415,674		$	162,246		$	—		$	—		$	—		$	—		$	—		$	577,920
		Year Ended December 31, 2013
		Crude			SemStream			SemCAMS			SemGas			SemLogistics			SemMexico			Corporate			Consolidated
																				and
																				Other
		(in thousands)
	Revenues:
	External	$	767,202		$	—		$	198,450		$	207,134		$	11,671		$	242,559		$	—		$	1,427,016
	Intersegment	—			—			—			23,985			—			—			(23,985		)	—
	Total revenues	767,202			—			198,450			231,119			11,671			242,559			(23,985		)	1,427,016
	Expenses:
	Costs of products sold, exclusive of depreciation and amortization shown below	663,759			—			305			169,800			380			209,841			(23,985		)	1,020,100
	Operating	36,242			1			150,319			20,200			7,444			9,379			—			223,585
	General and administrative	16,766			600			14,940			7,971			5,854			10,700			21,766			78,597
	Depreciation and amortization	23,708			—			10,766			14,517			9,426			5,991			2,001			66,409
	Loss (gain) on disposal of long-lived assets, net	(56		)	6			—			665			—			(854		)	—			(239		)
	Total expenses	740,419			607			176,330			213,153			23,104			235,057			(218		)	1,388,452
	Earnings from equity method investments	45,354			7,123			—			—			—			—			—			52,477
	Gain on issuance of common units by equity method investee	—			26,873			—			—			—			—			—			26,873
	Operating income (loss)	72,137			33,389			22,120			17,966			(11,433		)	7,502			(23,767		)	117,914
	Other expenses (income), net
	Interest expense (income)	14,923			(4,810		)	18,928			3,268			1,435			188			(8,790		)	25,142
	Other expense (income), net	(14		)	128			(20		)	(3		)	(400		)	(652		)	45,234			44,273
	Total other expenses (income)	14,909			(4,682		)	18,908			3,265			1,035			(464		)	36,444			69,415
	Income (loss) from continuing operations before income taxes	$	57,228		$	38,071		$	3,212		$	14,701		$	(12,468	)	$	7,966		$	(60,211	)	$	48,499
	Additions to long-lived assets	$	66,995		$	—		$	56,122		$	97,021		$	2,071		$	6,375		$	734		$	229,318
	Total assets at December 31, 2013 (excluding intersegment receivables)	$	1,070,484		$	208,847		$	306,001		$	552,095		$	168,835		$	104,154		$	60,198		$	2,470,614
	Equity investments at December 31, 2013	$	356,276		$	208,848		$	—		$	—		$	—		$	—		$	—		$	565,124
		Year Ended December 31, 2012
		Crude			SemStream			SemCAMS			SemGas			SemLogistics			SemMexico			Corporate			Consolidated
																				and
																				Other
		(in thousands)
	Revenues:
	External	$	620,797		$	7		$	223,219		$	117,264		$	12,341		$	263,870		$	(1	)	$	1,237,497
	Intersegment	—			—			—			10,606			—			—			(10,606		)	—
	Total revenues	620,797			7			223,219			127,870			12,341			263,870			(10,607		)	1,237,497
Expenses:
Costs of products sold, exclusive of depreciation and amortization shown below	546,966			33			768			100,677			196			236,851			(10,606		)	874,885
Operating	24,143			(37		)	174,284			12,712			5,921			7,677			—			224,700
General and administrative	13,321			930			14,020			6,195			5,652			9,433			22,367			71,918
Depreciation and amortization	12,131			—			10,589			7,043			9,780			6,171			2,496			48,210
Loss (gain) on disposal of long-lived assets, net	(3,501		)	214			—			46			—			(290		)	—			(3,531		)
Total expenses	593,060			1,140			199,661			126,673			21,549			259,842			14,257			1,216,182
Earnings from equity method investments	36,439			(403		)	—			—			—			—			—			36,036
Operating income (loss)	64,176			(1,536		)	23,558			1,197			(9,208		)	4,028			(24,864		)	57,351
Other expenses (income):
Interest expense (income)	(409		)	(3,449		)	18,727			1,461			2,486			314			(10,228		)	8,902
Other expense (income), net	31			(21		)	14			—			(420		)	(38		)	22,003			21,569
Total other expenses	(378		)	(3,470		)	18,741			1,461			2,066			276			11,775			30,471
Income (loss) from continuing operations before income taxes	$	64,554		$	1,934		$	4,817		$	(264	)	$	(11,274	)	$	3,752		$	(36,639	)	$	26,880
Additions to long-lived assets	$	41,364		$	—		$	13,340		$	47,140		$	1,188		$	3,396		$	14,827		$	121,255
Schedule of Segment Reporting Information by Segment Income Tax Expense (Benefit)	Income tax expense (benefit) relates to the following segments (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	SemCAMS	$	3,135		$	6,348		$	720
	SemLogistics	(2,231		)	(5,699		)	(7,736		)
	SemMexico	4,053			2,589			2,285
	Corporate and other	41,556			(20,492		)	2,653
	Total	$	46,513		$	(17,254	)	$	(2,078	)

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Components Of Inventories	Inventories consist of the following (in thousands):
		December 31,		December 31,
		2014		2013
	Crude oil	$	26,722	$	30,779
	Asphalt and other	16,810		13,516
	Total inventories	$	43,532	$	44,295

Other_Assets_Tables

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Other Assets [Abstract]
Other current assets	Other current assets consist of the following (in thousands):
		December 31,			December 31,
		2014			2013
	Prepaid expenses	$	5,989		$	5,696
	Deferred tax asset	5,897			7,325
	Other	8,131			990
	Total other current assets	$	20,017		$	14,011
Other noncurrent assets	Other noncurrent assets consist of the following (in thousands):
		December 31,			December 31,
		2014			2013
	Debt issuance costs, net	$	22,203	*	$	17,149	*
	Deferred tax asset	13,933			2,832
	Other	8,250			8,908
	Total other noncurrent assets, net	$	44,386		$	28,889
	* See Note 16 for discussion of debt issuance costs.

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Schedule Of Property, Plant And Equipment	Property, plant and equipment consists of the following (in thousands):
		December 31,			December 31,
		2014			2013
	Land	$	81,886		$	72,484
	Pipelines and related facilities	283,347			312,730
	Storage and terminal facilities	284,300			281,819
	Natural gas gathering and processing facilities	606,553			347,962
	Linefill	26,050			14,701
	Trucking equipment and other	40,392			31,978
	Office property and equipment	37,120			33,701
	Construction-in-progress	142,806			199,073
	Property, plant and equipment, gross	1,502,454			1,294,448
	Accumulated depreciation	(245,629		)	(188,720		)
	Property, plant and equipment, net	$	1,256,825		$	1,105,728

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill And Other Intangible Assets [Abstract]
Goodwill by Segment	Goodwill relates to the following segments (in thousands):
		December 31,			December 31,
		2014			2013
	Crude	$	36,116		$	28,322
	SemGas	13,052			23,839
	SemMexico	9,158			9,860
	Total Goodwill	$	58,326		$	62,021
Reconciliation of Goodwill	Changes in goodwill balances during the period from December 31, 2011 to December 31, 2014 are shown below (in thousands):
	Balance, December 31, 2011	$	9,453
	Currency translation adjustments	431
	Balance, December 31, 2012	9,884
	Barcas acquisition (Note 6)	28,322
	MMGS acquisition (Note 6)	23,839
	Currency translation adjustments	(24		)
	Balance, December 31, 2013	62,021
	Crude oil trucking asset acquisition (Note 6)	7,892
	MMGS purchase price allocation adjustment (Note 6)	(10,787		)
	Barcas purchase price allocation adjustment (Note 6)	(98		)
	Currency translation adjustments	(702		)
	Balance, December 31, 2014	$	58,326
Other Intangible Assets by Segment	Other intangible assets relate to the following segments (in thousands):
		December 31,			December 31,
		2014			2013
	Crude	$	16,640		$	5,775
	SemGas	152,383			163,144
	SemMexico	4,016			5,888
	Corporate and other	26			31
	Total other intangible assets	$	173,065		$	174,838
Reconciliation of Other Intangible Assets	Changes in other intangible asset balances are shown below (in thousands):
	Balance, December 31, 2011	$	8,950
	Amortization	(2,017		)
	Currency translation adjustments	652
	Balance, December 31, 2012	7,585
	Amortization	(6,018		)
	Barcas acquisition (Note 6)	6,930
	MMGS acquisition (Note 6)	166,332
	Currency translation adjustments	9
	Balance, December 31, 2013	174,838
	Amortization	(15,875		)
	Crude oil trucking asset acquisition (Note 6)	17,010
	MMGS purchase price allocation adjustment (Note 6)	(2,313		)
	Barcas purchase price allocation adjustment (Note 6)	(50		)
	Currency translation adjustments	(545		)
	Balance, December 31, 2014	$	173,065
Future Amortization of Other Intangible Assets	We estimate that future amortization of other intangible assets will be as follows (in thousands):
	For year ending:
	31-Dec-15	$	10,334
	31-Dec-16	10,928
	31-Dec-17	11,011
	31-Dec-18	10,918
	31-Dec-19	10,317
	Thereafter	119,557
	Total estimated amortization expense	$	173,065

Financial_Instruments_and_Conc1

Financial Instruments and Concentrations of Risk (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	The tables below summarize the balances of commodity derivative assets and liabilities at December 31, 2014 and 2013 (in thousands):
		December 31, 2014										December 31, 2013
	Derivatives subject to netting arrangements:	Level 1			Netting*				Total			Level 1		Netting*			Total
	Commodity derivatives:
	Assets	$	3,311		$	(1,637	)		$	1,674		$	36	$	(36	)	$	—
	Liabilities	$	1,637		$	(1,637	)		$	—		$	96	$	(36	)	$	60
	*	Relates primarily to exchange traded futures. Gain and loss positions on multiple contracts are settled net on a daily basis with the exchange.
Schedule of Notional Quantities for Commodity Derivative Instruments	The following table sets forth the notional quantities for derivative instruments entered into (in thousands of barrels):
		Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012
	Sales	6,773		2,595			1,743
	Purchases	6,477		2,575			1,636
Schedule of Derivatives Not Designated as Hedging Instruments Fair Value on Condensed Consolidated Balance Sheets	We have recorded the fair value of our commodity derivative instruments on our consolidated balance sheets in "other current assets" and "other current liabilities" in the following amounts (in thousands):
	December 31, 2014							December 31, 2013
	Other Current Assets			Other Current Liabilities				Other Current Assets			Other Current Liabilities
	$	1,674		$	—			$	—		$	60
Schedule of Realized and Unrealized Gains (Losses) from Commodity Derivatives	Realized and unrealized gains (losses) from our commodity derivatives were recorded to product revenue in the following amounts (in thousands):
	Year Ended December 31, 2014			Year Ended December 31, 2013				Year Ended December 31, 2012
	$	19,305		$	(1,593	)		$	149
Schedule of Foreign Assets and Liabilities	The following table summarizes the assets and liabilities (excluding affiliate balances) at December 31, 2014 of our subsidiaries outside the United States (in thousands):
		Canada			United				Mexico			Total
					Kingdom
	Cash and cash equivalents	$	17,710		$	957			$	13,253		$	31,920
	Other current assets	58,271			1,854				49,145			109,270
	Noncurrent assets	215,386			147,687				44,827			407,900
	Total assets	$	291,367		$	150,498			$	107,225		$	549,090
	Current liabilities	$	37,713		$	1,442			$	32,527		$	71,682
	Noncurrent liabilities	75,977			18,619				1,232			95,828
	Total liabilities	113,690			20,061				33,759			167,510
	Net assets	$	177,677		$	130,437			$	73,466		$	381,580

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Consolidated Income (Loss) From Continuing Operations	Our consolidated income from continuing operations before income taxes was generated in the following jurisdictions (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	U.S.	$	39,231		$	40,002		$	21,498
	Foreign	59,340			8,497			5,382
	Consolidated	$	98,571		$	48,499		$	26,880
Summary of Income Tax Expense (Benefit)	The following table summarizes income tax provision (benefit) from continuing operations by jurisdiction (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	Current income tax provision:
	Foreign	$	10,430		$	15,546		$	9,662
	U.S. federal	(195		)	2,067			—
	U.S. state	132			1,435			74
		10,367			19,048			9,736
	Deferred income tax provision (benefit):
	Foreign	2,024			(10,222		)	(12,070		)
	U.S. federal	30,074			(23,756		)	222
	U.S. state	4,048			(2,324		)	34
		36,146			(36,302		)	(11,814		)
	Provision (benefit) for income taxes	$	46,513		$	(17,254	)	$	(2,078	)
Reconciliation of Income Tax Provision (Benefit)	The following table reconciles income tax provision at the U.S. federal statutory rate to the consolidated provision (benefit) for income taxes (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	Income from continuing operations before income taxes	$	98,571		$	48,499		$	26,880
	U.S. federal statutory rate	35		%	35		%	35		%
	Provision at statutory rate	34,500			16,975			9,408
	State income taxes—net of federal benefit	3,197			(577		)	71
	Effect of rates other than statutory	(1,925		)	(1,041		)	(829		)
	Effect of U.S. taxation on foreign branches	20,769			2,974			1,883
	Foreign tax adjustment, prior years	(3,669		)	4,533			—
	Warrants	4,698			24,625			—
	Noncontrolling interest	(7,986		)	(6,096		)	(3,429		)
	Foreign tax credit and offset to branch deferreds	6,851			(2,876		)	(12,360		)
	Impact of valuation allowance on deferred tax assets	(7,331		)	(53,218		)	6,233
	Foreign net gain on subsidiary dissolution and debt waivers	(13,620		)	—			—
	Foreign withholding taxes	5,054			—			—
	Other, net	5,975			(2,553		)	(3,055		)
	Provision (benefit) for income taxes	$	46,513		$	(17,254	)	$	(2,078	)
Significant Components of Deferred Tax Assets and Liabilities	Significant components of deferred tax assets and liabilities are as follows at December 31, 2014 and 2013 (in thousands):
		December 31,			December 31,
		2014			2013
	Deferred tax assets:
	Net operating loss and other credit carryforwards	$	38,835		$	9,498
	Compensation and benefits	10,736			7,991
	Inventories	280			118
	Intangible assets	43,977			44,444
	Pension plan	3,733			2,849
	Allowance for doubtful accounts	1,860			2,140
	Deferred revenue	7,622			5,910
	Foreign tax credit and offset to branch deferreds	102,286			95,435
	Other	17,786			8,243
	less: valuation allowance	(102,769		)	(95,438		)
	Net deferred tax assets	124,346			81,190
	Deferred tax liabilities:
	Intangible assets	(5,770		)	(6,927		)
	Prepaid expenses	(163		)	(153		)
	Property, plant and equipment	(178,505		)	(113,030		)
	Equity investment in partnerships	(78,813		)	(49,720		)
	Other	(2,549		)	(1,471		)
	Total deferred tax liabilities	(265,800		)	(171,301		)
	Net deferred tax liabilities	$	(141,454	)	$	(90,111	)

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Instrument [Line Items]
Summary of Long-Term Debt	Our long-term debt consisted of the following (in thousands):
		December 31,		December 31,
		2014		2013
	SemGroup 7.50% senior unsecured notes	$	300,000	$	300,000
	SemGroup corporate revolving credit facility	35,000		70,000
	Rose Rock 5.625% senior unsecured notes	400,000		—
	Rose Rock credit facility	32,000		245,000
	SemMexico credit facility	—		—
	Capital leases	132		125
	Total long-term debt	767,132		615,125
	less: current portion of long-term debt	40		37
	Noncurrent portion of long-term debt	$	767,092	$	615,088
Scheduled Principal Payments of Debt	The following table summarizes the scheduled principal payments as of December 31, 2014 (in thousands). As described above, our debt agreements require accelerated principal payments under certain circumstances. As a result, principal payments may occur earlier than shown in the table below.
		Senior Unsecured Notes		Rose Rock Notes		SemGroup		Rose Rock		SemMexico		Capital		Total
						Facility		Facility		Facility		Leases
	For the year ended:
	31-Dec-15	$	—	$	—	$	—	$	—	$	—	$	40	$	40
	31-Dec-16	—		—		—		—		—		40		40
	31-Dec-17	—		—		—		—		—		26		26
	31-Dec-18	—		—		35,000		32,000		—		26		67,026
	31-Dec-19	—		—		—		—		—		—		—
	Thereafter	300,000		400,000		—		—		—		—		700,000
	Total	$	300,000	$	400,000	$	35,000	$	32,000	$	—	$	132	$	767,132
Senior Notes [Member] | Corporate Segment [Member]
Debt Instrument [Line Items]
Early Redemption Premium Percentages [Table Text Block]	From and after June 15, 2016, the Company may redeem the Notes, in whole or in part, at the redemption prices (expressed as percentages of principal amount) set forth below, plus accrued and unpaid interest, if redeemed during the twelve-month period beginning on June 15 of each of the years indicated below:
	Year		Percentage
	2016		105.62%
	2017		103.75%
	2018		101.88%
	2019 and thereafter		100.00%
Rose Rock Midstream L P [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Early Redemption Premium Percentages [Table Text Block]	From and after July 15, 2017, Rose Rock may redeem the Rose Rock Notes, in whole or in part, at the redemption prices (expressed as percentages of principal amount) set forth below, plus accrued and unpaid interest, if redeemed during the twelve-month period beginning on July 15 of each of the years indicated below:
	Year		Percentage
	2017		104.22%
	2018		102.81%
	2019		101.41%
	2020 and thereafter		100.00%

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Long-term Purchase Commitment [Line Items]
Long-term Purchase Commitment [Table Text Block]	The approximate amount of future obligation is as follows (in thousands):
	For year ending:
	31-Dec-15	$	10,199
	31-Dec-16	11,804
	31-Dec-17	11,938
	31-Dec-18	10,060
	31-Dec-19	9,121
	Thereafter	24,391
	Total expected future payments	$	77,513
Summary of Changes in Asset Retirement Obligations	The following table summarizes the changes in this liability from December 31, 2011 through December 31, 2014 (in thousands):
	Balance, December 31, 2011	$	35,886
	Accretion	4,554
	Payments made	(1,169		)
	Currency translation adjustments	834
	Balance, December 31, 2012	40,105
	Accretion	4,752
	Payments made	(808		)
	Currency translation adjustments	(2,864		)
	Balance, December 31, 2013	41,185
	Accretion	4,807
	Payments made	(514		)
	Currency translation adjustments	(3,524		)
	Balance, December 31, 2014	$	41,954
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Future minimum payments required under operating leases that have initial or remaining non-cancellable lease terms in excess of one year at December 31, 2014 are as follows (in thousands):
	For year ending:
	31-Dec-15	$	9,464
	31-Dec-16	9,181
	31-Dec-17	6,737
	31-Dec-18	2,997
	31-Dec-19	1,826
	Thereafter	6,967
	Total future minimum lease payments	$	37,172
Summary of Purchase and Sale Commitments [Table Text Block]	At December 31, 2014, such commitments included the following (in thousands):
		Volume			Value
		(barrels)
	Fixed price purchases	13,648			$	1,141,694
	Fixed price sales	13,612			$	1,152,966
	Floating price purchases	7,187			$	373,539
	Floating price sales	10,719			$	445,655

Equity_Tables

Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Schedule of common stock reflected on the consolidated balance sheet	The par value of common stock reflected on the consolidated balance sheet at December 31, 2014 is summarized below:
	Shares issued on Emergence Date	40,882,496
	Shares subsequently issued in settlement of pre-petition claims	517,500
	Issuance of shares under employee and director compensation programs*	861,503
	Shares issued under employee stock purchase plan	6,999
	Shares issued upon exercise of warrants**	1,345,556
	Total shares***	43,614,054
	Par value per share	$	0.01
	Par value of common stock at December 31, 2014 (in thousands)	$	436
	* These shares include 169,340 shares which vested during the year ended December 31, 2014. Of these vested shares, recipients sold back to the Company 11,120 shares to satisfy tax withholding obligations which are being recognized at cost as treasury stock on the consolidated balance sheet.
	** These shares include 904,231 shares issued during the year ended December 31, 2014.
Dividends Declared [Table Text Block]	The following table sets forth the quarterly dividends per share declared and paid to shareholders for the periods indicated:
	Quarter Ending	Dividend Per Share		Date Declared	Date of Record	Date Paid
	30-Jun-13	$	0.19	May 8, 2013	May 20, 2013	May 30, 2013
	30-Sep-13	$	0.2	August 8, 2013	August 19, 2013	August 30, 2013
	31-Dec-13	$	0.21	November 11, 2013	November 22, 2013	December 3, 2013
	31-Mar-14	$	0.22	February 25, 2014	March 10, 2014	March 20, 2014
	30-Jun-14	$	0.24	May 8, 2014	May 19, 2014	May 29, 2014
	30-Sep-14	$	0.27	August 6, 2014	August 18, 2014	August 28, 2014
	31-Dec-14	$	0.3	November 6, 2014	November 17, 2014	November 28, 2014
	31-Mar-15	$	0.34	February 26, 2015	March 9, 2015	March 20, 2015

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table Text Block]	The following summarizes the calculation of basic earnings per share for the years ended December 31, 2014, 2013 and 2012 (in thousands, except per share amounts):
		Year Ended December 31, 2014
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	52,058	$	(1	)	$	52,057
	less: Income attributable to noncontrolling interest	22,817		—			22,817
	Income attributable to SemGroup	$	29,241	$	(1	)	$	29,240
	Weighted average common stock outstanding	42,665		42,665			42,665
	Basic earnings per share	$	0.69	$	0		$	0.69
		Year Ended December 31, 2013
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	65,753	$	59		$	65,812
	less: Income attributable to noncontrolling interest	17,710		—			17,710
	Income attributable to SemGroup	$	48,043	$	59		$	48,102
	Weighted average common stock outstanding	42,339		42,339			42,339
	Basic earnings per share	$	1.13	$	0		$	1.14
		Year Ended December 31, 2012
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	28,958	$	2,939		$	31,897
	less: Income attributable to noncontrolling interest	9,797		—			9,797
	Income attributable to SemGroup	$	19,161	$	2,939		$	22,100
	Weighted average common stock outstanding	41,939		41,939			41,939
	Basic earnings per share	$	0.46	$	0.07		$	0.53
Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table Text Block]	The following summarizes the calculation of diluted earnings per share for the years ended December 31, 2014, 2013 and 2012 (in thousands, except per share amounts):
		Year Ended December 31, 2014
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	52,058	$	(1	)	$	52,057
	less: Income attributable to noncontrolling interest	22,817		—			22,817
	Income attributable to SemGroup	$	29,241	$	(1	)	$	29,240
	Weighted average common stock outstanding	42,665		42,665			42,665
	Effect of dilutive securities	302		302			302
	Diluted weighted average common stock outstanding	42,967		42,967			42,967
	Diluted earnings per share	$	0.68	$	0		$	0.68
		Year Ended December 31, 2013
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	65,753	$	59		$	65,812
	less: Income attributable to noncontrolling interest	17,710		—			17,710
	Income attributable to SemGroup	$	48,043	$	59		$	48,102
	Weighted average common stock outstanding	42,339		42,339			42,339
	Effect of dilutive securities	307		307			307
	Diluted weighted average common stock outstanding	42,646		42,646			42,646
	Diluted earnings per share	$	1.13	$	0		$	1.13
		Year Ended December 31, 2012
		Continuing		Discontinued			Net
		Operations		Operations
	Income	$	28,958	$	2,939		$	31,897
	less: Income attributable to noncontrolling interest	9,797		—			9,797
	Income attributable to SemGroup	$	19,161	$	2,939		$	22,100
	Weighted average common stock outstanding	41,939		41,939			41,939
	Effect of dilutive securities	315		315			315
	Diluted weighted average common stock outstanding	42,254		42,254			42,254
	Diluted earnings per share	$	0.45	$	0.07		$	0.52

EquityBased_Compensation_Table

Equity-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of unvested share activity	The activity related to these awards during the period from December 31, 2011 to December 31, 2014 is summarized below:
		Unvested			Average		Aggregate Fair Value of Shares (in thousands)
		Shares			Grant Date
					Fair Value
	Outstanding at December 31, 2011	410,506			$	26.59
	Awards granted - 2012	246,432			$	27.81
	Awards vested - 2012	(162,986	)		$	25.2	$	4,107
	Awards forfeited - 2012	(43,400	)		$	27.74
	Outstanding at December 31, 2012	450,552			$	26.87
	Awards granted - 2013	201,451			$	52.78
	Awards vested - 2013	(107,988	)		$	25.71	$	2,776
	Awards forfeited - 2013	(13,412	)		$	32.36
	Outstanding at December 31, 2013	530,603			$	36.8
	Awards granted - 2014	207,786			$	77.14
	Awards vested - 2014	(169,340	)		$	33.07	$	5,600
	Awards forfeited - 2014	(119,130	)		$	42.16
	Outstanding at December 31, 2014	449,919			$	70.69
Schedule of Share-based Payment Award Valuation Assumptions [Table Text Block]	The following table sets forth the assumptions used in the valuations of these awards granted in 2014, 2013 and 2012:
		2014		2013
	Volatility	29.30%		28.90%
	Risk-free interest rate	0.66%		0.35%
Rose Rock equity incentive plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of unvested share activity	The activity related to these awards is summarized below:
		Unvested Units			Average Grant Date Fair Value		Aggregate Fair Value of Units (in thousands)
	Outstanding at December 31, 2011	—			$	—
	Awards granted - 2012	46,069			$	21.97
	Awards vested - 2012	—			$	—	$	—
	Awards forfeited - 2012	(2,109	)		$	20.6
	Outstanding at December 31, 2012	43,960			$	21.91
	Awards granted - 2013	49,104			$	34.41
	Awards vested - 2013	(9,333	)		$	27.25	$	254
	Awards forfeited - 2013	(783	)		$	34.4
	Outstanding at December 31, 2013	82,948			$	28.59
	Awards granted - 2014	46,536			$	41.35
	Awards vested - 2014	(5,712	)		$	35.87	$	205
	Awards forfeited - 2014	(21,432	)		$	29.82
	Outstanding at December 31, 2014	102,340			$	33.79

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Weighted Average Discount Rate [Line Items]
Projected benefit obligations and plan assets of the pension plans	The following table shows the projected benefit obligations and plan assets of the Pension Plans (in thousands):
		December 31,				December 31,
		2014				2013
	Change in projected benefit obligation:
	Projected benefit obligation at beginning of year	$	24,036			$	28,357
	Service cost	477				577
	Interest cost	1,080				1,047
	Actuarial (gains) losses	6,228				(3,022		)
	Benefits paid	(521		)		(968		)
	Currency translation adjustment	(2,034		)		(1,955		)
	Projected benefit obligation at end of year	29,266				24,036
	Change in fair value of plan assets:
	Fair value of plan assets at beginning of year	25,582				22,727
	Employer contributions	601				1,144
	Actual return on plan assets	2,915				4,397
	Benefits paid	(521		)		(968		)
	Currency translation adjustment	(2,209		)		(1,718		)
	Fair value of plan assets at end of year	26,368				25,582
	Funded status:	$	(2,898	)		$	1,546
	Accumulated benefit obligation at end of year	$	26,544			$	22,687
Components of the net periodic benefit cost related to the pension plans	The following table summarizes the components of the net periodic benefit cost related to the Pension Plans (in thousands):
		Year Ended December 31, 2014				Year Ended December 31, 2013				Year Ended December 31, 2012
	Service cost	$	477			$	577			$	596
	Interest cost	1,080				1,047				1,134
	Expected return on plan assets	(1,469		)		(1,298		)		(1,263		)
	Settlement loss	—				—				(55		)
	Other	(7		)		186				118
	Net periodic benefit cost	$	81			$	512			$	530
Estimate of benefit payments from the pension plans	We estimate that benefit payments from the Pension Plans will be as follows for the years 2015 – 2024 (in thousands):
	Year		Estimated
			Benefit Payments
	2015		$	4,800
	2016		$	2,809
	2017		$	2,046
	2018		$	987
	2019		$	1,114
	2020 - 2024		$	12,178
Target allocation of plan assets	The following table shows the value of each category of plan assets at December 31, 2014 and 2013 and the target investment allocation under our investment policy at December 31, 2014:
		Asset Value at				Asset Value at				Actual			Normal			Minimum			Maximum
		December 31,				December 31,				Allocation at			Allocation			Allocation			Allocation
		2014				2013				December 31,			Per			Per			Per
		(in thousands)				(in thousands)				2014			Investment			Investment			Investment
													Policy			Policy			Policy
	Cash and cash equivalents	$	—			$	171			0	%		—	%		0	%		10	%
	Pooled funds—fixed income	8,938				8,381				33.9	%		40	%		32.5	%		47.5	%
	Pooled funds—Canadian equities	8,828				8,324				33.5	%		30	%		22.5	%		37.5	%
	Pooled funds—non-Canadian equities	8,602				8,706				32.6	%		30	%		22.5	%		37.5	%
	Total	$	26,368			$	25,582
Fair values of defined benefit plan assets [Table Text Block]	The following information discloses the fair values of our Pension Plan assets, by asset category, for the periods indicated (in thousands):
		December 31, 2014										December 31, 2013
		Quoted Price in Active Markets for Identical Assets (Level 1)			Significant Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)				Quoted Price in Active Markets for Identical Assets (Level 1)			Significant Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
	Cash and cash equivalents	$	—		$	—		$	—			$	171		$	—		$	—
	Fixed income mutual funds (a)	—			8,938			—				—			8,381			—
	Equity mutual funds (a)	—			17,430			—				—			17,030			—
	Total	$	—		$	26,368		$	—			$	171		$	25,411		$	—
	(a) Mutual funds are valued daily in actively traded markets by an independent custodian for the investment manager. For purposes of calculating the value, portfolio securities and other assets for which market quotes are readily available are valued at market value. Market value is generally determined on a basis of last reported sales prices, or if no sales are reported, based on quotes obtained from a quotation reporting system, established market makers, or pricing services. Investments initially valued in currencies other than the U.S. dollar are converted to the U.S. dollar using exchange rates obtained from pricing services.
Projected benefit obligation assumptions [Member]
Weighted Average Discount Rate [Line Items]
Schedule of Assumptions Used [Table Text Block]	The following table sets forth the assumptions used to determine the projected benefit obligation of the Pension Plans for the periods indicated:
		Year Ended December 31, 2014			Year Ended December 31, 2013
	Discount rate	3.8	%		4.7	%
	Compensation increase rate	4.5	%		3.5	%
Net periodic benefit cost assumptions [Member]
Weighted Average Discount Rate [Line Items]
Schedule of Assumptions Used [Table Text Block]	The following table sets forth the assumptions used to determine net periodic benefit cost related to the Pension Plans for the periods indicated:
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	Discount rate	4.7	%		3.9	%		4.25	%
	Expected long-term rate of return on plan assets	6	%		6	%		6	%
	Compensation increase rate	3.5	%		3.5	%		3.5	%

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Components of accumulated other comprehensive income (loss)	The following table presents changes in the components of accumulated other comprehensive income (loss) (in thousands):
		Currency			Employee			Interest			Total
		Translation			Benefit			Rate Swaps
					Plans
	Balance, December 31, 2011	$	(10,780	)	$	(2,811	)	$	(284	)	$	(13,875	)
	Currency translation adjustment, net of income tax expense of $1,168	12,635			—			—			12,635
	Settlement of interest rate swaps	—			—			284			284
	Changes related to benefit plans, net of income tax benefit of $117	—			(343		)	—			(343		)
	Balance, December 31, 2012	1,855			(3,154		)	—			(1,299		)
	Currency translation adjustment, net of income tax benefit of $3,993	(6,363		)	—			—			(6,363		)
	Changes related to benefit plans, net of income tax expense of $1,603	—			4,808			—			4,808
	Balance, December 31, 2013	(4,508		)	1,654			—			(2,854		)
	Currency translation adjustment, net of income tax benefit of $11,102	(20,551		)	—			—			(20,551		)
	Changes related to benefit plans, net of income tax benefit of $1,245	—			(3,736		)	—			(3,736		)
	Balance, December 31, 2014	$	(25,059	)	$	(2,082	)	$	—		$	(27,141	)

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Information [Abstract]
Schedule of Changes in Operating Assets and Liabilities	The following table summarizes the changes in the components of operating assets and liabilities, net of the effects of acquisitions (in thousands):
		Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
	Decrease (increase) in restricted cash	$	(2,045	)	$	29,467		$	4,907
	Decrease (increase) in accounts receivable	(32,602		)	11,172			(129,102		)
	Decrease (increase) in receivable from affiliates	50,454			(61,095		)	230
	Decrease (increase) in inventories	(6,243		)	(11,352		)	(936		)
	Decrease (increase) in derivatives and margin deposits	28			1,012			(1,245		)
	Decrease (increase) in other current assets	(614		)	9,361			4,197
	Decrease (increase) in other assets	2			137			2,467
	Increase (decrease) in accounts payable and accrued liabilities	11,461			31,030			114,776
	Increase (decrease) in payable to affiliates	(48,819		)	62,279			(6,871		)
	Increase (decrease) in payables to pre-petition creditors	(54		)	(29,609		)	(5,206		)
	Increase (decrease) in other noncurrent liabilities	5,067			(2,541		)	2,500
		$	(23,365	)	$	39,861		$	(14,283	)

Quarterly_Financial_Data_Table

Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Data [Abstract]
Summarized Information on the Consolidated Results of Operations	Summarized information on our consolidated results of operations for the quarters during the year ended December 31, 2014 is shown below (in thousands, except per share amounts):
		First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	Total revenues	$	498,883		$	482,224		$	594,235		$	547,237		$	2,122,579
	Loss (gain) on disposal or impairment of long-lived assets, net	(58		)	19,315			1,376			11,959			32,592
	Other operating costs and expenses	478,264			471,863			575,936			530,150			2,056,213
	Total expenses	478,206			491,178			577,312			542,109			2,088,805
	Earnings from equity method investments	14,962			19,187			14,223			15,827			64,199
	Gain on issuance of common units by equity method investee	8,127			—			18,772			2,121			29,020
	Operating income	43,766			10,233			49,918			23,076			126,993
	Other expenses (income), net	7,497			29,489			(6,368		)	(2,196		)	28,422
	Income (loss) from continuing operations before income taxes	36,269			(19,256		)	56,286			25,272			98,571
	Income tax expense (benefit)	16,526			(6,672		)	24,090			12,569			46,513
	Income (loss) from continuing operations	19,743			(12,584		)	32,196			12,703			52,058
	Income (loss) from discontinued operations, net of income taxes	(5		)	—			—			4			(1		)
	Net income (loss)	19,738			(12,584		)	32,196			12,707			52,057
	Less: net income attributable to noncontrolling interests	6,150			5,025			6,934			4,633			22,817
	Net income (loss) attributable to SemGroup	$	13,588		$	(17,609	)	$	25,262		$	8,074		$	29,240
	Earnings (loss) per share—basic	$	0.32		$	(0.41	)	$	0.59		$	0.19		$	0.69
	Earnings (loss) per share—diluted	$	0.29		$	(0.41	)	$	0.59		$	0.18		$	0.68
	Summarized information on our consolidated results of operations for the quarters during the year ended December 31, 2013 is shown below (in thousands, except per share amounts):
		First			Second			Third			Fourth			Total
		Quarter			Quarter			Quarter			Quarter
	Total revenues	$	287,696		$	324,244		$	357,748		$	457,328		$	1,427,016
	Loss (gain) on disposal of long-lived assets, net	(162		)	(376		)	408			(109		)	(239		)
	Other operating costs and expenses	282,813			312,103			344,979			448,796			1,388,691
	Total expenses	282,651			311,727			345,387			448,687			1,388,452
	Earnings from equity method investments	17,345			14,861			7,483			12,788			52,477
	Gain on issuance of common units by equity method investee	—			—			—			26,873			26,873
	Operating income	22,390			27,378			19,844			48,302			117,914
	Other expenses, net	27,862			10,613			13,294			17,646			69,415
	Income (loss) from continuing operations before income taxes	(5,472		)	16,765			6,550			30,656			48,499
	Income tax expense (benefit)	(54,006		)	9,288			3,413			24,051			(17,254		)
	Income from continuing operations	48,534			7,477			3,137			6,605			65,753
	Income (loss) from discontinued operations, net of income taxes	32			35			(2		)	(6		)	59
	Net income	48,566			7,512			3,135			6,599			65,812
	Less: net income attributable to noncontrolling interests	5,143			3,943			5,054			3,319			17,710
	Net income (loss) attributable to SemGroup	$	43,423		$	3,569		$	(1,919	)	$	3,280		$	48,102
	Earnings (loss) per share—basic	$	1.03		$	0.08		$	(0.05	)	$	0.08		$	1.14
	Earnings (loss) per share—diluted	$	1.03		$	0.08		$	(0.05	)	$	0.08		$	1.13

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	During the years ended December 31, 2014, 2013 and 2012, we generated the following transactions with NGL Energy and its subsidiaries (in thousands):
		Year Ended December 31, 2014		Year Ended December 31, 2013		Year Ended December 31, 2012
	Revenues	$	456,987	$	796,440	$	421,311
	Purchases	$	437,015	$	669,450	$	336,612
	Reimbursements from NGL Energy for services	$	168	$	198	$	575

Condensed_Consolidating_Guaran1

Condensed Consolidating Guarantor Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Condensed Balance Sheet [Table Text Block]	Condensed Consolidating Guarantor Balance Sheets
		31-Dec-14
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	ASSETS
	Current assets:
	Cash and cash equivalents	$	9,254		$	—		$	35,486		$	(4,142	)	$	40,598
	Restricted cash	3,856			—			3,124			—			6,980
	Accounts receivable	9,669			32,932			308,733			—			351,334
	Receivable from affiliates	2,512			6,628			15,655			(7,976		)	16,819
	Inventories	—			248			43,284			—			43,532
	Other current assets	10,498			615			8,904			—			20,017
	Total current assets	35,789			40,423			415,186			(12,118		)	479,280
	Property, plant and equipment	4,112			512,508			740,205			—			1,256,825
	Equity method investments	1,551,825			692,872			269,634			(1,936,411		)	577,920
	Goodwill	—			13,052			45,274			—			58,326
	Other intangible assets	26			152,383			20,656			—			173,065
	Other noncurrent assets, net	24,555			958			18,873			—			44,386
	Total assets	$	1,616,307		$	1,412,196		$	1,509,828		$	(1,948,529	)	$	2,589,802
	LIABILITIES AND OWNERS’ EQUITY
	Current liabilities:
	Accounts payable	$	649		$	22,477		$	234,051		$	—		$	257,177
	Payable to affiliates	21			52			21,363			(7,976		)	13,460
	Accrued liabilities	11,989			19,154			61,549			2			92,694
	Payables to pre-petition creditors	3,129			—			—			—			3,129
	Deferred revenue	—			—			23,688			—			23,688
	Other current liabilities	224			707			543			—			1,474
	Current portion of long-term debt	—			—			40			—			40
	Total current liabilities	16,012			42,390			341,234			(7,974		)	391,662
	Long-term debt	335,000			—			490,946			(58,854		)	767,092
	Deferred income taxes	112,897			—			49,059			—			161,956
	Other noncurrent liabilities	2,886			—			46,769			—			49,655
	Commitments and contingencies
	Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	1,149,512			1,369,806			511,891			(1,881,701		)	1,149,508
	Noncontrolling interests in consolidated subsidiaries	—			—			69,929			—			69,929
	Total owners’ equity	1,149,512			1,369,806			581,820			(1,881,701		)	1,219,437
	Total liabilities and owners’ equity	$	1,616,307		$	1,412,196		$	1,509,828		$	(1,948,529	)	$	2,589,802
		31-Dec-13
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	ASSETS
	Current assets:
	Cash and cash equivalents	$	2,545		$	—		$	78,364		$	(1,558	)	$	79,351
	Restricted cash	3,851			—			1,268			—			5,119
	Accounts receivable	649			14,642			308,674			—			323,965
	Receivable from affiliates	1,519			14,063			56,040			(4,349		)	67,273
	Inventories	—			1,046			43,249			—			44,295
	Other current assets	8,712			193			5,106			—			14,011
	Total current assets	17,276			29,944			492,701			(5,907		)	534,014
	Property, plant and equipment	4,114			366,067			735,547			—			1,105,728
	Equity method investments	1,511,922			461,056			159,321			(1,567,175		)	565,124
	Goodwill	—			23,839			38,182			—			62,021
	Other intangible assets	31			163,144			11,663			—			174,838
	Other noncurrent assets, net	15,263			1,302			12,324			—			28,889
	Total assets	$	1,548,606		$	1,045,352		$	1,449,738		$	(1,573,082	)	$	2,470,614
	LIABILITIES AND OWNERS’ EQUITY
	Current liabilities:
	Accounts payable	$	1,172		$	24,234		$	229,061		$	—		$	254,467
	Payable to affiliates	17			115			67,062			(4,915		)	62,279
	Accrued liabilities	10,072			17,341			56,011			5			83,429
	Payables to pre-petition creditors	3,124			—			53			—			3,177
	Deferred revenue	—			—			25,538			—			25,538
	Other current liabilities	61,875			715			7,697			—			70,287
	Current portion of long-term debt	—			—			37			—			37
	Total current liabilities	76,260			42,405			385,459			(4,910		)	499,214
	Long-term debt	370,000			—			245,088			—			615,088
Deferred income taxes	48,436			—			52,509			—			100,945
Other noncurrent liabilities	8			—			41,496			—			41,504
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	1,053,902			1,002,947			565,225			(1,568,172		)	1,053,902
Noncontrolling interests in consolidated subsidiaries	—			—			159,961			—			159,961
Total owners’ equity	1,053,902			1,002,947			725,186			(1,568,172		)	1,213,863
Total liabilities and owners’ equity	$	1,548,606		$	1,045,352		$	1,449,738		$	(1,573,082	)	$	2,470,614
Condensed Income Statement [Table Text Block]	Condensed Consolidating Guarantor Statements of Operations
		Year Ended December 31, 2014
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	Revenues:
	Product	$	—		$	338,621		$	1,479,543		$	(37,850	)	$	1,780,314
	Service	—			44,592			188,647			—			233,239
	Other	—			—			109,026			—			109,026
	Total revenues	—			383,213			1,777,216			(37,850		)	2,122,579
	Expenses:
	Costs of products sold, exclusive of depreciation and amortization shown below	—			273,309			1,387,899			(37,850		)	1,623,358
	Operating	—			33,591			213,022			—			246,613
	General and administrative	22,394			10,796			54,655			—			87,845
	Depreciation and amortization	1,678			29,677			67,042			—			98,397
	Loss (gain) loss on disposal or impairment of long-lived assets, net	5,945			54,698			(28,051		)	—			32,592
	Total expenses	30,017			402,071			1,694,567			(37,850		)	2,088,805
	Earnings from equity method investments	48,760			102,866			49,620			(137,047		)	64,199
	Gain on issuance of common units by equity method investee	29,020			—			—			—			29,020
	Operating income	47,763			84,008			132,269			(137,047		)	126,993
	Other expenses (income):
	Interest expense	8,423			19,186			24,740			(3,305		)	49,044
	Foreign currency transaction gain	—			—			(86		)	—			(86		)
	Other expense (income), net	(24,092		)	500			(246		)	3,302			(20,536		)
	Total other expenses (income), net	(15,669		)	19,686			24,408			(3		)	28,422
	Income from continuing operations before income taxes	63,432			64,322			107,861			(137,044		)	98,571
	Income tax expense	34,192			—			12,321			—			46,513
	Income from continuing operations	29,240			64,322			95,540			(137,044		)	52,058
	Loss from discontinued operations, net of income taxes	—			—			(1		)	—			(1		)
	Net income	29,240			64,322			95,539			(137,044		)	52,057
	Less: net income attributable to noncontrolling interests	—			—			22,817			—			22,817
	Net income attributable to SemGroup	$	29,240		$	64,322		$	72,722		$	(137,044	)	$	29,240
	Net income	$	29,240		$	64,322		$	95,539		$	(137,044	)	$	52,057
	Other comprehensive income (loss), net of income taxes	5,159			—			(29,446		)	—			(24,287		)
	Comprehensive income	34,399			64,322			66,093			(137,044		)	27,770
	Less: comprehensive income attributable to noncontrolling interests	—			—			22,817			—			22,817
	Comprehensive income attributable to SemGroup	$	34,399		$	64,322		$	43,276		$	(137,044	)	$	4,953
		Year Ended December 31, 2013
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	Revenues:
	Product	$	—		$	224,072		$	944,984		$	(23,952	)	$	1,145,104
	Service	—			3,868			136,330			—			140,198
	Other	—			—			141,714			—			141,714
	Total revenues	—			227,940			1,223,028			(23,952		)	1,427,016
	Expenses:
	Costs of products sold, exclusive of depreciation and amortization shown below	—			166,735			877,317			(23,952		)	1,020,100
	Operating	—			19,541			204,044			—			223,585
	General and administrative	21,560			9,437			47,600			—			78,597
	Depreciation and amortization	2,001			14,452			49,956			—			66,409
	Loss (gain) on disposal of long-lived assets, net	—			668			(907		)	—			(239		)
	Total expenses	23,561			210,833			1,178,010			(23,952		)	1,388,452
	Earnings from equity method investments	67,965			54,995			44,203			(114,686		)	52,477
	Gain on issuance of common units by equity method investee	26,873			—			—			—			26,873
	Operating income	71,277			72,102			89,221			(114,686		)	117,914
	Other expenses (income):
	Interest expense	4,826			9,781			15,947			(5,412		)	25,142
	Foreign currency transaction gain	—			—			(1,633		)	—			(1,633		)
	Other expense (income), net	40,928			—			(434		)	5,412			45,906
	Total other expenses, net	45,754			9,781			13,880			—			69,415
	Income from continuing operations before income taxes	25,523			62,321			75,341			(114,686		)	48,499
	Income tax expense (benefit)	(22,579		)	—			5,325			—			(17,254		)
	Income from continuing operations	48,102			62,321			70,016			(114,686		)	65,753
	Income (loss) from discontinued operations, net of income taxes	—			65			(6		)	—			59
	Net income	48,102			62,386			70,010			(114,686		)	65,812
	Less: net income attributable to noncontrolling interests	—			—			17,710			—			17,710
	Net income attributable to SemGroup	$	48,102		$	62,386		$	52,300		$	(114,686	)	$	48,102
Net income	$	48,102		$	62,386		$	70,010		$	(114,686	)	$	65,812
Other comprehensive loss, net of income taxes	(1,517		)	—			(38		)	—			(1,555		)
Comprehensive income	46,585			62,386			69,972			(114,686		)	64,257
Less: comprehensive income attributable to noncontrolling interests	—			—			17,710			—			17,710
Comprehensive income attributable to SemGroup	$	46,585		$	62,386		$	52,262		$	(114,686	)	$	46,547
	Year Ended December 31, 2012
	Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
Revenues:
Product	$	—		$	123,424		$	840,892		$	(10,578	)	$	953,738
Service	—			1,198			116,523			—			117,721
Other	—			387			165,651			—			166,038
Total revenues	—			125,009			1,123,066			(10,578		)	1,237,497
Expenses:
Costs of products sold, exclusive of depreciation and amortization shown below	—			98,224			787,239			(10,578		)	874,885
Operating	—			12,719			211,981			—			224,700
General and administrative	22,105			8,360			41,453			—			71,918
Depreciation and amortization	2,496			6,448			39,266			—			48,210
Loss (gain) on disposal of long-lived assets, net	—			276			(3,807		)	—			(3,531		)
Total expenses	24,601			126,027			1,076,132			(10,578		)	1,216,182
Earnings from equity method investments	66,671			85,330			36,439			(152,404		)	36,036
Operating income	42,070			84,312			83,373			(152,404		)	57,351
Other expenses (income):
Interest expense	3,942			(240		)	11,056			(5,856		)	8,902
Foreign currency transaction loss	—			—			298			—			298
Other expense (income), net	15,698			(21		)	(262		)	5,856			21,271
Total other expenses (income), net	19,640			(261		)	11,092			—			30,471
Income from continuing operations before income taxes	22,430			84,573			72,281			(152,404		)	26,880
Income tax (benefit) expense	334			—			(2,412		)	—			(2,078		)
Income from continuing operations	22,096			84,573			74,693			(152,404		)	28,958
Income (loss) from discontinued operations, net of income taxes	4			(17		)	2,952			—			2,939
Net income	22,100			84,556			77,645			(152,404		)	31,897
Less: net income attributable to noncontrolling interests	—			—			9,797			—			9,797
Net income attributable to SemGroup	$	22,100		$	84,556		$	67,848		$	(152,404	)	$	22,100
Net income	$	22,100		$	84,556		$	77,645		$	(152,404	)	$	31,897
Other comprehensive income, net of income taxes	917			—			11,659			—			12,576
Comprehensive income	23,017			84,556			89,304			(152,404		)	44,473
Less: comprehensive income attributable to noncontrolling interests	—			—			9,797			—			9,797
Comprehensive income attributable to SemGroup	$	23,017		$	84,556		$	79,507		$	(152,404	)	$	34,676
Condensed Cash Flow Statement [Table Text Block]	Condensed Consolidating Guarantor Statements of Cash Flows
		Year Ended December 31, 2014
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	Net cash provided by operating activities	$	27,393		$	56,178		$	188,376		$	(90,289	)	$	181,658
	Cash flows from investing activities:
	Capital expenditures	(1,672		)	(180,361		)	(88,473		)	—			(270,506		)
	Proceeds from sale of long-lived assets	—			2,368			2,077			—			4,445
	Contributions to equity method investments	—			(16,201		)	(54,930		)	—			(71,131		)
	Payments to acquire businesses	—			(514		)	(43,994		)	—			(44,508		)
	Proceeds from sale of common units of equity method investee	79,741			—			—			—			79,741
	Proceeds from the sale of interest in SemCrude Pipeline, L.L.C. to Rose Rock Midstream L.P.	114,412			—			—			(114,412		)	—
	Distributions in excess of equity in earnings of affiliates	1,843			2,344			9,390			(1,843		)	11,734
	Net cash provided by (used in) investing activities	194,324			(192,364		)	(175,930		)	(116,255		)	(290,225		)
	Cash flows from financing activities:
	Debt issuance costs	(93		)	—			(8,593		)	—			(8,686		)
	Borrowings on credit facilities and issuance of senior unsecured notes	405,500			—			848,744			—			1,254,244
	Principal payments on credit facilities and other obligations	(440,500		)	—			(661,772		)	—			(1,102,272		)
	Distributions to noncontrolling interests	—			—			(28,494		)	—			(28,494		)
	Proceeds from warrant exercises	1,451			—			—			—			1,451
	Repurchase of common stock for payment of statutory taxes due on equity-based compensation	(719		)	—			—			—			(719		)
	Dividends paid	(44,206		)	—			—			—			(44,206		)
	Proceeds from issuance of common stock under employee stock purchase plan	340			—			—			—			340
	Excess tax benefit from equity-based awards	1,650			—			—			—			1,650
	Intercompany borrowings (advances), net	(138,431		)	136,186			(201,715		)	203,960			—
	Net cash provided by (used in) financing activities	(215,008		)	136,186			(51,830		)	203,960			73,308
	Effect of exchange rate changes on cash and cash equivalents	—			—			(3,494		)	—			(3,494		)
	Change in cash and cash equivalents	6,709			—			(42,878		)	(2,584		)	(38,753		)
	Cash and cash equivalents at beginning of period	2,545			—			78,364			(1,558		)	79,351
	Cash and cash equivalents at end of period	$	9,254		$	—		$	35,486		$	(4,142	)	$	40,598
		Year Ended December 31, 2013
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	Net cash provided by (used in) operating activities	$	20,130		$	24,642		$	148,872		$	(20,235	)	$	173,409
	Cash flows from investing activities:
	Capital expenditures	(734		)	(123,246		)	(91,629		)	—			(215,609		)
	Proceeds from sale of long-lived assets	23			19			1,237			—			1,279
	Contributions to equity method investments	(18,775		)	(57,850		)	(97,243		)	—			(173,868		)
	Payments to acquire businesses	—			(313,487		)	(48,969		)	—			(362,456		)
	Proceeds from the sale of interest in SemCrude Pipeline, L.L.C. to Rose Rock Midstream, L.P.	362,600			—			—			(362,600		)	—
	Distributions in excess of equity in earnings of affiliates	—			—			12,246			—			12,246
	Net cash provided by (used in) investing activities	343,114			(494,564		)	(224,358		)	(362,600		)	(738,408		)
	Cash flows from financing activities:
	Debt issuance costs	(10,866		)	—			(4,070		)	—			(14,936		)
	Borrowings on debt	706,000			—			562,474			—			1,268,474
	Principal payments on debt and other obligations	(537,500		)	—			(321,912		)	—			(859,412		)
	Proceeds from issuance of Rose Rock Midstream, L.P. common units, net of offering costs	—			—			210,226			—			210,226
	Distributions to noncontrolling interests	—			—			(17,647		)	—			(17,647		)
	Proceeds from warrant exercises	225			—			—			—			225
	Repurchase of common stock	(371		)	—			—			—			(371		)
	Dividends paid	(25,429		)	—			—			—			(25,429		)
	Intercompany borrowings (advances), net	(511,881		)	469,922			(342,256		)	384,215			—
	Net cash provided by (used in) financing activities	(379,822		)	469,922			86,815			384,215			561,130
	Effect of exchange rate changes on cash and cash equivalents	—			—			3,191			—			3,191
	Change in cash and cash equivalents	(16,578		)	—			14,520			1,380			(678		)
	Cash and cash equivalents at beginning of period	19,123			—			63,844			(2,938		)	80,029
	Cash and cash equivalents at end of period	$	2,545		$	—		$	78,364		$	(1,558	)	$	79,351
		Year Ended December 31, 2012
		Parent			Guarantors			Non-guarantors			Consolidating Adjustments			Consolidated
	Net cash provided by (used in) operating activities	$	(4,535	)	$	6,236		$	93,534		$	(15,593	)	$	79,642
	Cash flows from investing activities:
	Capital expenditures	(1,977		)	(59,317		)	(58,025		)	—			(119,319		)
	Proceeds from sale of long-lived assets	19			(202		)	2,824			—			2,641
	Contributions to equity method investments	(1,740		)	(74,434		)	(2,079		)	—			(78,253		)
	Proceeds from the sale of non-consolidated affiliate	—			—			3,500			—			3,500
	Proceeds from the sale of SemStream assets	12,250			—			—			—			12,250
Distributions in excess of equity in earnings of affiliates	9,218			—			8,072			—			17,290
Net cash provided by (used in) investing activities	17,770			(133,953		)	(45,708		)	—			(161,891		)
Cash flows from financing activities:
Debt issuance costs	(455		)	—			(252		)	—			(707		)
Borrowings on credit facilities	318,000			—			—			—			318,000
Principal payments on credit facilities and other obligations	(194,000		)	—			(28,066		)	—			(222,066		)
Distributions to noncontrolling interests	—			—			(8,502		)	—			(8,502		)
Repurchase of common stock	(242		)	—			—			—			(242		)
Intercompany borrowings (advances), net	(117,526		)	127,717			(25,608		)	15,417			—
Net cash provided by (used in) financing activities	5,777			127,717			(62,428		)	15,417			86,483
Effect of exchange rate changes on cash and cash equivalents	—			—			(610		)	—			(610		)
Change in cash and cash equivalents	19,012			—			(15,212		)	(176		)	3,624
Change in cash and cash equivalents included in discontinued operations	—			—			2,792			—			2,792
Change in cash and cash equivalents from continuing operations	19,012			—			(12,420		)	(176		)	6,416
Cash and cash equivalents at beginning of period	111			—			76,264			(2,762		)	73,613
Cash and cash equivalents at end of period	$	19,123		$	—		$	63,844		$	(2,938	)	$	80,029

Overview_Details

Overview (Details)	12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014
Rose Rock Midstream L P [Member]
Schedule Of Overview [Line Items]
General partner ownership interest	2.00%
Crude [Member]
Schedule Of Overview [Line Items]
Length of pipeline network (in miles)	570
Oil storage capacity, barrels	7,600,000
Trucks	255
Trailers	275
SemCAMS [Member]
Schedule Of Overview [Line Items]
Gas processing plants	4
Gas plant operating capacity	695
SemGas [Member]
Schedule Of Overview [Line Items]
Gas processing plants	4
Gas plant operating capacity	388
SemLogistics [Member]
Schedule Of Overview [Line Items]
Oil storage capacity, barrels	8,700,000
SemMexico [Member]
Schedule Of Overview [Line Items]
Number of plants	1
Number of rail unloading facilities	1
Asphalt cement terminals and modification facilities	14
General Partner [Member] | Rose Rock Midstream L P [Member]
Schedule Of Overview [Line Items]
General partner ownership interest	2.00%
General Partner [Member] | Crude [Member] | Rose Rock Midstream L P [Member]
Schedule Of Overview [Line Items]
General partner ownership interest	2.00%
Limited Partner [Member] | Crude [Member] | Rose Rock Midstream L P [Member]
Schedule Of Overview [Line Items]
Limited partner ownership interest	56.80%
White Cliffs Pipeline, LLC [Member]
Schedule Of Overview [Line Items]
Equity method investment, ownership percentage	51.00%
Width of Pipeline	12
White Cliffs Pipeline, LLC [Member] | Crude [Member]
Schedule Of Overview [Line Items]
Length of pipeline network (in miles)	527
Equity method investment, ownership percentage	51.00%
pipelines	2
Width of Pipeline	12
Glass Mountain Pipeline LLC [Member] | Crude [Member]
Schedule Of Overview [Line Items]
Length of pipeline network (in miles)	210
Equity method investment, ownership percentage	50.00%
Ngl Energy Partners Lp [Member] | General Partner [Member] | SemStream [Member]
Schedule Of Overview [Line Items]
Equity method investment, ownership percentage	11.78%
Partnership Interest [Member] | Glass Mountain Pipeline LLC [Member]
Schedule Of Overview [Line Items]
Equity method investment, ownership percentage	50.00%
Partnership Interest [Member] | Ngl Energy Partners Lp [Member] | Limited Partner [Member] | SemStream [Member]
Schedule Of Overview [Line Items]
Investments in and Advances to Affiliates, Balance, Shares	6,652,101
Equity method investment, ownership percentage		7.50%

Consolidation_And_Basis_Of_Pre1

Consolidation And Basis Of Presentation (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Consolidation And Basis Of Presentation [Line Items]
Property, plant and equipment	$1,256,825,000	$1,105,728,000
SemCAMS [Member] | Proportionally Consolidated Assets [Member]
Consolidation And Basis Of Presentation [Line Items]
Property, plant and equipment	209,800,000
White Cliffs Pipeline, LLC [Member]
Consolidation And Basis Of Presentation [Line Items]
Equity method investment, ownership percentage	51.00%
White Cliffs Pipeline, LLC [Member] | Semcrude Pipeline [Member]
Consolidation And Basis Of Presentation [Line Items]
Equity method investment, ownership percentage	51.00%
White Cliffs Pipeline, LLC [Member] | Crude [Member]
Consolidation And Basis Of Presentation [Line Items]
Equity method investment, ownership percentage	51.00%
Glass Mountain Pipeline LLC [Member] | Crude [Member]
Consolidation And Basis Of Presentation [Line Items]
Equity method investment, ownership percentage	50.00%
Semcrude Pipeline [Member] | Common control transaction [Member] | Rose Rock Midstream L P [Member]
Consolidation And Basis Of Presentation [Line Items]
Gain (loss) sale of interest in SemCrude Pipeline, L.L.C. to subsidiary	$0

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2014
Pipelines and related facilities [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	10 years
Pipelines and related facilities [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	31 years
Storage and terminal facilities [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	10 years
Storage and terminal facilities [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	25 years
Natural gas gathering and processing facilities [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	10 years
Natural gas gathering and processing facilities [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	31 years
Trucking equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	3 years
Trucking equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	7 years
Office and Other Property and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	3 years
Office and Other Property and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life property, plant and equipment (in years)	31 years

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details Textual) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Summary Of Significant Accounting Policies [Line Items]
Payables to pre-petition creditors	3,129	$3,177
Restricted cash	6,980	5,119
Number of countries in which segments operate	4
Restricted Cash For Settlement Purposes [Member]
Summary Of Significant Accounting Policies [Line Items]
Restricted cash	3,800
SemCAMS [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage mark-up on pass-through of recoverable maintenance costs	10.00%
Minimum [Member] | SemCAMS [Member]
Summary Of Significant Accounting Policies [Line Items]
Maintenance period	4 years
Maximum [Member] | SemCAMS [Member]
Summary Of Significant Accounting Policies [Line Items]
Maintenance period	5 years
Other Current Liabilities [Member] | Discontinued Operations [Member]
Summary Of Significant Accounting Policies [Line Items]
Payables to pre-petition creditors	700

Rose_Rock_Midstream_LP_Details

Rose Rock Midstream, L.P. (Details 1) (Rose Rock Midstream L P [Member])	12 Months Ended
	Dec. 31, 2014
Minimum Quarterly Distributions [Member]
Quarterly Target Distributions
Marginal Percentage Interest, Unitholders	98.00%
Marginal Percentage Interest, General Partner	2.00%
Marginal Percentage Interest, Incentive Distribution Rights	0.00%
Minimum Quarterly Distributions [Member] | Minimum [Member]
Quarterly Target Distributions
Partners' minimum quarterly distribution per unit	0.3625
First Target Distribution [Member]
Quarterly Target Distributions
Marginal Percentage Interest, Unitholders	98.00%
Marginal Percentage Interest, General Partner	2.00%
Marginal Percentage Interest, Incentive Distribution Rights	0.00%
First Target Distribution [Member] | Minimum [Member]
Quarterly Target Distributions
Partners' minimum quarterly distribution per unit	0.3625
First Target Distribution [Member] | Maximum [Member]
Quarterly Target Distributions
Partners' minimum quarterly distribution per unit	0.416875
Second Target Distribution [Member]
Quarterly Target Distributions
Marginal Percentage Interest, Unitholders	85.00%
Marginal Percentage Interest, General Partner	2.00%
Marginal Percentage Interest, Incentive Distribution Rights	13.00%
Second Target Distribution [Member] | Minimum [Member]
Quarterly Target Distributions
Partners' minimum quarterly distribution per unit	0.416875
Second Target Distribution [Member] | Maximum [Member]
Quarterly Target Distributions
Partners' minimum quarterly distribution per unit	0.453125
Third Target Distribution [Member]
Quarterly Target Distributions
Marginal Percentage Interest, Unitholders	75.00%
Marginal Percentage Interest, General Partner	2.00%
Marginal Percentage Interest, Incentive Distribution Rights	23.00%
Third Target Distribution [Member] | Minimum [Member]
Quarterly Target Distributions
Partners' minimum quarterly distribution per unit	0.453125
Third Target Distribution [Member] | Maximum [Member]
Quarterly Target Distributions
Partners' minimum quarterly distribution per unit	0.54375
Thereafter [Member]
Quarterly Target Distributions
Marginal Percentage Interest, Unitholders	50.00%
Marginal Percentage Interest, General Partner	2.00%
Marginal Percentage Interest, Incentive Distribution Rights	48.00%
Thereafter [Member] | Minimum [Member]
Quarterly Target Distributions
Partners' minimum quarterly distribution per unit	0.54375

Rose_Rock_Midstream_LP_Details1

Rose Rock Midstream, L.P. (Details 2) (Rose Rock Midstream L P [Member], USD $)

0 Months Ended

In Thousands, except Per Share data, unless otherwise specified

Feb. 13, 2012

15-May-12

Aug. 14, 2012

Nov. 14, 2012

Feb. 14, 2013

15-May-13

Aug. 14, 2013

Nov. 14, 2013

Feb. 14, 2014

15-May-14

Aug. 14, 2014

Nov. 14, 2014

Feb. 13, 2015

Distribution of Q4 2011 earnings (pro-rated) [Member]

Distributions Paid

Distribution per unit

$0.07

[1]

Total distributions

$1,147

Distribution of Q1 2012 earnings [Member]

Distributions Paid

Distribution per unit

$0.37

Total distributions

6,377

Distribution of Q2 2012 earnings [Member]

Distributions Paid

Distribution per unit

$0.38

Total distributions

6,550

Distribution of Q3 2012 earnings [Member]

Distributions Paid

Distribution per unit

$0.39

Total distributions

6,721

Distribution of Q4 2012 earnings [Member]

Distributions Paid

Distribution per unit

$0.40

Total distributions

8,331

Distribution of Q1 2013 earnings [Member]

Distributions Paid

Distribution per unit

$0.43

Total distributions

8,941

Distribution of Q2 2013 earnings [Member]

Distributions Paid

Distribution per unit

$0.44

Total distributions

9,180

Distribution of Q3 2013 earnings [Member]

Distributions Paid

Distribution per unit

$0.45

Total distributions

11,624

Distribution of Q4 2013 earnings [Member]

Distributions Paid

Distribution per unit

$0.47

Total distributions

12,841

Distribution of Q1 2014 earnings [Member]

Distributions Paid

Distribution per unit

$0.50

Total distributions

13,903

Distribution of Q2 2014 earnings [Member]

Distributions Paid

Distribution per unit

$0.54

Total distributions

16,718

Distribution of Q3 2014 earnings [Member]

Distributions Paid

Distribution per unit

$0.57

Total distributions

18,866

Subsequent Event [Member] | Distribution of Q4 2014 earnings [Member]

Distributions Paid

Distribution per unit

$0.62

[2]

Total distributions

24,269

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q4 2011 earnings (pro-rated) [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

470

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q1 2012 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

2,607

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q2 2012 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

2,678

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q3 2012 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

2,748

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q4 2012 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

3,624

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q1 2013 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

3,872

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q2 2013 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

3,962

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q3 2013 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

6,189

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q4 2013 earnings [Member]

Distributions Paid

Limited partner distributions

6,398

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q1 2014 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

6,811

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q2 2014 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

7,362

Limited Partner [Member] | Noncontrolling Interest [Member] | Distribution of Q3 2014 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

7,912

Limited Partner [Member] | Noncontrolling Interest [Member] | Subsequent Event [Member] | Distribution of Q4 2014 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

8,544

Limited Partner [Member] | Parent [Member] | Distribution of Q4 2011 earnings (pro-rated) [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

93

Limited Partner [Member] | Parent [Member] | Distribution of Q4 2011 earnings (pro-rated) [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

561

Limited Partner [Member] | Parent [Member] | Distribution of Q1 2012 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

517

Limited Partner [Member] | Parent [Member] | Distribution of Q1 2012 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

3,125

Limited Partner [Member] | Parent [Member] | Distribution of Q2 2012 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

532

Limited Partner [Member] | Parent [Member] | Distribution of Q2 2012 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

3,209

Limited Partner [Member] | Parent [Member] | Distribution of Q3 2012 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

545

Limited Partner [Member] | Parent [Member] | Distribution of Q3 2012 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

3,294

Limited Partner [Member] | Parent [Member] | Distribution of Q4 2012 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

1,163

Limited Partner [Member] | Parent [Member] | Distribution of Q4 2012 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

3,377

Limited Partner [Member] | Parent [Member] | Distribution of Q1 2013 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

1,242

Limited Partner [Member] | Parent [Member] | Distribution of Q1 2013 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

3,607

Limited Partner [Member] | Parent [Member] | Distribution of Q2 2013 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

1,271

Limited Partner [Member] | Parent [Member] | Distribution of Q2 2013 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

3,692

Limited Partner [Member] | Parent [Member] | Distribution of Q3 2013 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

1,301

Limited Partner [Member] | Parent [Member] | Distribution of Q3 2013 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

3,775

Limited Partner [Member] | Parent [Member] | Distribution of Q4 2013 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

2,041

Limited Partner [Member] | Parent [Member] | Distribution of Q4 2013 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

3,901

Limited Partner [Member] | Parent [Member] | Distribution of Q1 2014 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

2,173

Limited Partner [Member] | Parent [Member] | Distribution of Q1 2014 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

4,153

Limited Partner [Member] | Parent [Member] | Distribution of Q2 2014 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

3,646

Limited Partner [Member] | Parent [Member] | Distribution of Q2 2014 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

4,488

Limited Partner [Member] | Parent [Member] | Distribution of Q3 2014 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

3,918

Limited Partner [Member] | Parent [Member] | Distribution of Q3 2014 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

4,824

Limited Partner [Member] | Parent [Member] | Subsequent Event [Member] | Distribution of Q4 2014 earnings [Member] | Common Unit [Member]

Distributions Paid

Limited partner distributions

6,551

Limited Partner [Member] | Parent [Member] | Subsequent Event [Member] | Distribution of Q4 2014 earnings [Member] | Subordinated Units [Member]

Distributions Paid

Limited partner distributions

5,202

General Partner [Member] | Parent [Member] | Distribution of Q4 2011 earnings (pro-rated) [Member]

Distributions Paid

General partner distributions

23

Incentive distributions

0

General Partner [Member] | Parent [Member] | Distribution of Q1 2012 earnings [Member]

Distributions Paid

General partner distributions

128

Incentive distributions

0

General Partner [Member] | Parent [Member] | Distribution of Q2 2012 earnings [Member]

Distributions Paid

General partner distributions

131

Incentive distributions

0

General Partner [Member] | Parent [Member] | Distribution of Q3 2012 earnings [Member]

Distributions Paid

General partner distributions

134

Incentive distributions

0

General Partner [Member] | Parent [Member] | Distribution of Q4 2012 earnings [Member]

Distributions Paid

General partner distributions

167

Incentive distributions

0

General Partner [Member] | Parent [Member] | Distribution of Q1 2013 earnings [Member]

Distributions Paid

General partner distributions

179

Incentive distributions

41

General Partner [Member] | Parent [Member] | Distribution of Q2 2013 earnings [Member]

Distributions Paid

General partner distributions

183

Incentive distributions

72

General Partner [Member] | Parent [Member] | Distribution of Q3 2013 earnings [Member]

Distributions Paid

General partner distributions

232

Incentive distributions

127

General Partner [Member] | Parent [Member] | Distribution of Q4 2013 earnings [Member]

Distributions Paid

General partner distributions

257

Incentive distributions

244

General Partner [Member] | Parent [Member] | Distribution of Q1 2014 earnings [Member]

Distributions Paid

General partner distributions

278

Incentive distributions

488

General Partner [Member] | Parent [Member] | Distribution of Q2 2014 earnings [Member]

Distributions Paid

General partner distributions

334

Incentive distributions

888

General Partner [Member] | Parent [Member] | Distribution of Q3 2014 earnings [Member]

Distributions Paid

General partner distributions

377

Incentive distributions

1,835

General Partner [Member] | Parent [Member] | Subsequent Event [Member] | Distribution of Q4 2014 earnings [Member]

Distributions Paid

General partner distributions

485

Incentive distributions

$3,487

[1]

*Minimum quarterly distribution for quarter ended December 31, 2011 was prorated for the period beginning immediately after the closing of Rose Rock’s IPO, December 14, 2011 through December 31, 2011.

[2]

** The distribution to common unitholders related to earnings for the quarter ended December 31, 2014 was payable on February 13, 2015 to holders of record at February 3, 2015. As such, the Class A units, which converted to common units on January 1, 2015, were eligible for the distribution which is reflected in the amount paid to common unitholders.

Rose_Rock_Midstream_LP_Details2

Rose Rock Midstream, L.P. (Details 3) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Summarized Balance Sheet Information
Other current assets	$20,017	$14,011
Property, plant and equipment	1,256,825	1,105,728
Equity method investments	577,920	565,124
Goodwill	58,326	62,021	9,884	9,453
Other noncurrent assets	44,386	28,889
Total assets	2,589,802	2,470,614
Current liabilities	391,662	499,214
Long-term debt	767,092	615,088
Noncontrolling interest in consolidated subsidiaries retained by SemGroup	69,929	159,961
Total liabilities and owners’ equity	2,589,802	2,470,614
Rose Rock Midstream L P [Member]
Summarized Balance Sheet Information
Cash	3,666	15,459
Other current assets	270,224	306,128
Property, plant and equipment	335,910	311,616
Equity method investments	269,635	224,095
Goodwill	36,116	28,322
Other noncurrent assets	29,677	11,627
Total assets	945,228	897,247
Current liabilities	263,680	293,031
Long-term debt	432,092	245,088
Partners’ capital attributable to SemGroup	179,527	120,610
Limited Partners' Capital Account	69,929
Partners’ capital attributable to noncontrolling interests		159,961
Noncontrolling interest in consolidated subsidiaries retained by SemGroup	0	78,557
Total liabilities and owners’ equity	$945,228	$897,247

Rose_Rock_Midstream_LP_Details3

Rose Rock Midstream, L.P. (Details 4) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summarized Income Statement Information
Revenue	$547,237	$594,235	$482,224	$498,883	$457,328	$357,748	$324,244	$287,696	$2,122,579	$1,427,016	$1,237,497
Costs of products sold									1,623,358	1,020,100	874,885
Depreciation and amortization expense									98,397	66,409	48,210
Earnings from equity method investments	15,827	14,223	19,187	14,962	12,788	7,483	14,861	17,345	64,199	52,477	36,036
Net income (loss)	12,707	32,196	-12,584	19,738	6,599	3,135	7,512	48,566	52,057	65,812	31,897
Less: net income attributable to noncontrolling interests	4,633	6,934	5,025	6,150	3,319	5,054	3,943	5,143	22,817	17,710	9,797
Net Income (Loss) Attributable to Parent	8,074	25,262	-17,609	13,588	3,280	-1,919	3,569	43,423	29,240	48,102	22,100
Rose Rock Midstream L P [Member]
Summarized Income Statement Information
Revenue									1,290,644	766,526	620,417
Costs of products sold									1,131,362	663,759	546,966
Operating, general and administrative expenses									97,575	51,082	35,385
Depreciation and amortization expense									36,072	23,165	12,131
Earnings from equity method investments									57,378	17,571	0
Net income (loss)									62,577	38,005	23,954
Less: net income attributable to noncontrolling interests									7,758	1,256	0
Net Income (Loss) Attributable to Parent									$54,819	$36,749	$23,954

Rose_Rock_Midstream_LP_Details4

Rose Rock Midstream, L.P. (Details Textual) (USD $)	12 Months Ended			0 Months Ended	1 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 11, 2013	Aug. 30, 2013	Aug. 31, 2013	Jun. 23, 2014	Dec. 16, 2013	Feb. 17, 2015	Jan. 02, 2015	Feb. 13, 2015
Proceeds from Sale of Equity Method Investments	$79,741,000	$0	$0
Sale of interest in equity investment to related party	-31,930,000	-67,291,000
Tax effect of adjustment to APIC from sale of equity investment to less than wholly owned subsidiary	31,930,000	67,291,000
Rose Rock Midstream L P [Member]
General partner ownership interest	2.00%
Proceeds from lines of credit				133,500,000
Semcrude Pipeline [Member]
Gain on sale of interests in SemCrude Pipeline	0	0
Common Units [Member] | Rose Rock Midstream L P [Member]
Common units representing limited partner interests	6,814,709
Limited Partners' Capital Account, Units Issued					4,750,000
Subordinated Units [Member] | Rose Rock Midstream L P [Member]
Common units representing limited partner interests	8,389,709
Class A [Member] | Rose Rock Midstream L P [Member]
Common units representing limited partner interests	3,750,000
Private Placement [Member] | Common Units [Member] | Rose Rock Midstream L P [Member]
Common units sold in public offering				2,000,000
Proceeds from issuance of common stock				59,300,000
Glass Mountain Pipeline Llc [Member] | Partnership Interest [Member]
Equity method investment, ownership percentage	50.00%
White Cliffs Pipeline, LLC [Member]
Equity method investment, ownership percentage	51.00%
Average daily throughput threshold in barrels for conversion of Class A units	125,000
White Cliffs Pipeline, LLC [Member] | Semcrude Pipeline [Member]
Equity method investment, ownership percentage	51.00%
General Partner [Member] | Rose Rock Midstream L P [Member]
General partner ownership interest	2.00%
Common Units [Member] | Rose Rock Midstream L P [Member]
Proceeds from Issuance of Common Limited Partners Units						152,500,000
Noncontrolling Interest [Member]
Sale of interest in equity investment to related party	-85,173,000	-180,220,000
Additional Paid-in Capital [Member]
Sale of interest in equity investment to related party	53,243,000	112,929,000
Third contribution of 33% Interest in SemCrude Pipeline [Domain] | Semcrude Pipeline [Member]
Equity method investment, ownership percentage							33.00%
Third contribution of 33% Interest in SemCrude Pipeline [Domain] | Rose Rock Midstream L P [Member] | Common Units [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received							2,425,000
Third contribution of 33% Interest in SemCrude Pipeline [Domain] | Rose Rock Midstream L P [Member] | Class A [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received							1,250,000
Third contribution of 33% Interest in SemCrude Pipeline [Domain] | Rose Rock Midstream L P [Member] | Semcrude Pipeline [Member]
Proceeds from Sale of Equity Method Investments							114,400,000
Initial contribution of 33% Interest in SemCrude Pipeline [Member] [Member] | Semcrude Pipeline [Member]
Equity method investment, ownership percentage				33.00%
Initial contribution of 33% Interest in SemCrude Pipeline [Member] [Member] | Rose Rock Midstream L P [Member] | Common Units [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received				1,500,000
Initial contribution of 33% Interest in SemCrude Pipeline [Member] [Member] | Rose Rock Midstream L P [Member] | Class A [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received				1,250,000
Initial contribution of 33% Interest in SemCrude Pipeline [Member] [Member] | Rose Rock Midstream L P [Member] | Semcrude Pipeline [Member]
Proceeds from Sale of Equity Method Investments				189,500,000
Second contribution of 33% Interest in SemCrude Pipeline [Member] | Semcrude Pipeline [Member]
Equity method investment, ownership percentage								33.00%
Second contribution of 33% Interest in SemCrude Pipeline [Member] | Rose Rock Midstream L P [Member] | Common Units [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received								1,500,000
Second contribution of 33% Interest in SemCrude Pipeline [Member] | Rose Rock Midstream L P [Member] | Class A [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received								1,250,000
Second contribution of 33% Interest in SemCrude Pipeline [Member] | Rose Rock Midstream L P [Member] | Semcrude Pipeline [Member]
Proceeds from Sale of Equity Method Investments								173,100,000
SemCrude Pipeline Acquisition Transactions [Member]
Transaction costs expensed	900,000	2,200,000
SemCrude Pipeline Acquisition Transactions [Member] | Rose Rock Midstream L P [Member]
Transaction costs expensed	400,000	900,000
Equity issuance costs paid from proceeds		1,600,000
SemCrude Pipeline Acquisition Transactions [Member] | Revolving Credit Facility [Member] | Rose Rock Midstream L P [Member]
Deferred borrowing costs		1,600,000
Minimum [Member] | First Target Distribution [Member] | Rose Rock Midstream L P [Member]
Partners' minimum quarterly distribution per unit	0.3625
Crude [Member] | Glass Mountain Pipeline Llc [Member]
Equity method investment, ownership percentage	50.00%
Crude [Member] | White Cliffs Pipeline, LLC [Member]
Equity method investment, ownership percentage	51.00%
Crude [Member] | General Partner [Member] | Rose Rock Midstream L P [Member]
General partner ownership interest	2.00%
Crude [Member] | Limited Partner [Member] | Rose Rock Midstream L P [Member]
Limited partner ownership interest	56.80%
Crude [Member] | Limited Partner [Member] | Semcrude Pipeline [Member] | Rose Rock Midstream L P [Member]
Limited partner ownership interest	100.00%
Subsequent Event [Member] | Subordinated Units [Member] | Rose Rock Midstream L P [Member]
Limited partners' capital account, units converted to common									8,389,709
Subsequent Event [Member] | Class A [Member] | Rose Rock Midstream L P [Member]
Limited partners' capital account, units converted to common										3,750,000
Subsequent Event [Member] | Wattenberg Oil Trunkline and Glass Mountain Pipeline [Member] | Common Units [Member] | Rose Rock Midstream L P [Member]
Common units sold in public offering											2,300,000
Proceeds from issuance of common stock											89,100,000
Subsequent Event [Member] | Wattenberg Oil Trunkline and Glass Mountain Pipeline [Member] | Rose Rock Midstream L P [Member]
Proceeds from Sale of Equity Method Investments											$251,200,000
Subsequent Event [Member] | Wattenberg Oil Trunkline and Glass Mountain Pipeline [Member] | Rose Rock Midstream L P [Member] | Common Units [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received											1,750,000

Equity_Method_Investments_Inve

Equity Method Investments (Investment Summary) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Equity method investments	$577,920				$565,124				$577,920		$565,124
Earnings from equity method investments	15,827	14,223	19,187	14,962	12,788	7,483	14,861	17,345	64,199		52,477		36,036
Proceeds from Equity Method Investment, Dividends or Distributions, Return of and Return on Capital									96,995		75,897		53,731
White Cliffs Pipeline, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments	269,635				224,095				269,635		224,095
Earnings from equity method investments									57,378		45,459		36,439
Proceeds from Equity Method Investment, Dividends or Distributions, Return of and Return on Capital									66,768		57,576		44,514
Ngl Energy Partners Lp [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments	162,246				208,848				162,246		208,848
Earnings from equity method investments									2,343	[1]	7,123	[1]	-403
Proceeds from Equity Method Investment, Dividends or Distributions, Return of and Return on Capital									23,404		18,321		9,217
Glass Mountain Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments	146,039				132,181				146,039		132,181
Earnings from equity method investments									4,478		-105		0
Proceeds from Equity Method Investment, Dividends or Distributions, Return of and Return on Capital									$6,823		$0		$0
[1]	* Excluding gains on issuance of common units of $29.0 million and $26.9 million for the years ended December 31, 2014 and 2013, respectively.

Equity_Method_Invesments_Summa

Equity Method Invesments (Summarized Balance Sheet Information) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
White Cliffs Pipeline, LLC [Member]
Current assets	$35,623	$98,457
Property, plant and equipment, net	471,179	312,831
Goodwill	17,000	17,000
Other intangible assets, net	16,043	20,802
Total assets	539,845	449,090
Current liabilities	11,108	9,648
Members’ equity	528,737	439,442
Total liabilities and members’ equity	539,845	449,090
Glass Mountain Pipeline LLC [Member]
Current assets	8,810
Property, plant and equipment, net	215,876
Total assets	224,686
Current liabilities	2,643
Other liabilities	42
Members’ equity	222,001
Total liabilities and members’ equity	224,686
Ngl Energy Partners Lp [Member]
Current assets	2,585,053	1,013,859
Property, plant and equipment, net	1,433,313	631,663
Goodwill	1,170,490	840,287
Other intangible assets, net	1,362,823	540,684
Total assets	6,551,679	3,026,493
Current liabilities	1,759,980	800,658
Long-term debt	2,437,351	906,066
Other noncurrent liabilities	39,518	2,673
Members’ equity	2,314,830	1,317,096
Total liabilities and members’ equity	$6,551,679	$3,026,493

Equity_Method_Investments_Summ

Equity Method Investments (Summarized Income Statement Information) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
White Cliffs Pipeline, LLC [Member]
Summarized income statement information
Revenue	$160,369	$133,310	$108,125
Operating, general and administrative expenses	23,067	23,825	14,821
Depreciation and amortization expense	23,257	18,668	19,963
Net income	114,045	90,817	73,341
Glass Mountain Pipeline LLC [Member]
Summarized income statement information
Revenue	30,398
Operating, general and administrative expenses	7,176
Depreciation and amortization expense	13,872
Net income	9,344
Ngl Energy Partners Lp [Member]
Summarized income statement information
Revenue				15,748,520	5,935,715	2,371,524
Costs of products sold				15,054,291	5,478,361	2,182,263
Operating, general and administrative expenses				440,609	276,905	125,889
Depreciation and amortization expense				162,443	94,050	34,621
Net income				$11,409	$44,378	$5,405

Equity_Method_Investments_Deta

Equity Method Investments (Details Textual) (USD $)	3 Months Ended								12 Months Ended			3 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2015	Oct. 27, 2014
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Gain on issuance of common units by equity method investee	$2,121,000	$18,772,000	$0	$8,127,000	$26,873,000	$0	$0	$0	$29,020,000	$26,873,000	$0
General and administrative expenses									87,845,000	78,597,000	71,918,000
Share price	$68.39								$68.39
Proceeds from Sale of Equity Method Investments									79,741,000	0	0
Equity Method Investment, Realized Gain (Loss) on Disposal									34,211,000	0	0
White Cliffs Pipeline, LLC [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
General and administrative expenses									1,600,000	1,800,000	2,000,000
SemStream [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Gain on issuance of common units by equity method investee									29,020,000	26,873,000
General and administrative expenses									83,000	600,000	930,000
White Cliffs Pipeline, LLC [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Percentage of ownership interest	51.00%								51.00%
Width of Pipeline									12
Ngl Energy Partners Lp [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Gain on issuance of common units by equity method investee									29,000,000	26,900,000
Share price	$27.99								$27.99
Units of equity investee divested									2,481,308
Proceeds from Sale of Equity Method Investments									88,800,000
Proceeds from Sale of Equity Method Investments									79,700,000
Ngl Energy Partners Lp [Member] | NGL Energy Holdings LLC [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Number of Seats on the Board of Directors													2
Ngl Energy Partners Lp [Member] | Subsequent Event [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Units of equity investee divested												999,533
Proceeds from Sale of Equity Method Investments												29,000,000
Transaction related costs												400,000
Equity Method Investment, Realized Gain (Loss) on Disposal												7,500,000
Glass Mountain Pipeline LLC [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Partners' Capital Account, Contributions									16,200,000	57,800,000
Equity Method Goodwill	31,000,000								31,000,000
Accumulated Capitalized Interest Costs	4,100,000								4,100,000
Partnership Interest [Member] | Glass Mountain Pipeline LLC [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Percentage of ownership interest	50.00%								50.00%
Limited Partner [Member] | Partnership Interest [Member] | Ngl Energy Partners Lp [Member] | SemStream [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Percentage of ownership interest		7.50%
Investments in and Advances to Affiliates, Balance, Shares	6,652,101								6,652,101
General Partner [Member] | Ngl Energy Partners Lp [Member] | SemStream [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Percentage of ownership interest	11.78%								11.78%
Pipeline expansion [Member] | White Cliffs Pipeline, LLC [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Incremental capacity expected to be added									65,000
Expected capital contributions, year one									40,000,000
Pipeline capacity	150,000								150,000
Partners' Capital Account, Contributions									53,300,000	95,500,000	2,300,000
Other Nonoperating Income (Expense) [Member] | Ngl Energy Partners Lp [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Transaction related costs									3,100,000
Equity Method Investment, Realized Gain (Loss) on Disposal									34,200,000
Fair Value, Inputs, Level 1 [Member] | Ngl Energy Partners Lp [Member]
Investment in Non Consolidated Subsidiaries (Textual) [Abstract]
Equity Method Investment, Quoted Market Value	$186,200,000								$186,200,000

Acquisitions_Acquisitions_Deta

Acquisitions Acquisitions (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 24, 2014	Jun. 23, 2014
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Goodwill	$58,326	$62,021	$9,884	$9,453
Crude [Member]
Business Acquisition [Line Items]
Goodwill	36,116	28,322
Crude [Member] | Chesapeake crude oil trucking assets [Member]
Business Acquisition [Line Items]
Property, plant, and equipment acquired						19,092
Customer contract intangible asset acquired					17,000	17,010
Goodwill						7,892
Total assets acquired						$43,994

Acquisitions_Details_1

Acquisitions (Details 1) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Aug. 01, 2013
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Goodwill acquired	$58,326	$62,021	$9,884	$9,453
SemGas [Member]
Business Acquisition [Line Items]
Goodwill acquired	13,052	23,839
SemGas [Member] | Mid-America Midstream Gas Services, LLC [Member]
Business Acquisition [Line Items]
Property, plant, and equipment acquired					136,949
Customer contract intangible asset acquired					164,000
Goodwill acquired					13,052
Total assets acquired					$314,001

Acquisitions_Details_2

Acquisitions (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 02, 2013
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Goodwill acquired	$58,326	$62,021	$9,884	$9,453
Crude [Member]
Business Acquisition [Line Items]
Goodwill acquired	36,116	28,322
Crude [Member] | Barcas Field Services, LLC [Member]
Business Acquisition [Line Items]
Property, plant, and equipment acquired					13,865
Customer contract intangible asset acquired					6,880
Goodwill acquired					28,234
Total assets acquired					$48,979

Acquisitions_Details_Textual

Acquisitions (Details Textual) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended		1 Months Ended
	Jun. 25, 2014	Dec. 31, 2014	Sep. 02, 2013	Aug. 01, 2013	Jun. 30, 2014	Sep. 28, 2012	Jun. 23, 2014	Sep. 01, 2013	Aug. 06, 2013
							Trucks
							Trailers
Business Acquisition [Line Items]
Senior notes		$300,000,000
Partnership Interest [Member] | Glass Mountain Pipeline LLC [Member]
Business Acquisition [Line Items]
Equity method investment, ownership percentage		50.00%
Additional interest acquired [Member] | Partnership Interest [Member] | Glass Mountain Pipeline LLC [Member]
Business Acquisition [Line Items]
Equity method investment, ownership percentage						25.00%
Senior Notes [Member]
Business Acquisition [Line Items]
Debt instrument, interest rate stated percentage		7.50%
Crude [Member] | Chesapeake crude oil trucking assets [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment		-2,600,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles		12,600,000
Goodwill, Purchase Accounting Adjustments		-10,000,000
Payments to acquire businesses	44,000,000
Trucks purchased							124
Trailers purchased							122
Estimated probability of contract renewal							95.00%
Crude [Member] | Barcas Field Services, LLC [Member]
Business Acquisition [Line Items]
Goodwill, Purchase Accounting Adjustments		-98,000
Payments to acquire businesses			48,969,000
Trucks purchased			114
Trailers purchased			120
Estimated probability of contract renewal								50.00%
Crude [Member] | Glass Mountain Pipeline LLC [Member]
Business Acquisition [Line Items]
Equity method investment, ownership percentage		50.00%
SemGas [Member] | Mid-America Midstream Gas Services, LLC [Member]
Business Acquisition [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles					-2,300,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred		500,000
Goodwill, Purchase Accounting Adjustments		-10,787,000			-10,800,000
Payments to acquire businesses				314,001,000
Transaction costs expensed				$3,600,000
Length of gathering pipeline acquired				200
Net acre dedication acquired				540,000
SemGas [Member] | Rose Valley I plant [Member] | Mid-America Midstream Gas Services, LLC [Member]
Business Acquisition [Line Items]
Processing capacity				200
SemGas [Member] | Rose Valley II plant [Member] | Mid-America Midstream Gas Services, LLC [Member]
Business Acquisition [Line Items]
Processing capacity				200
SemGas [Member] | Gathering and processing agreement [Member] | Mid-America Midstream Gas Services, LLC [Member]
Business Acquisition [Line Items]
Contract tenor				20 years
Percentage of contract which is fee based				100.00%
SemStream [Member] | General Partner [Member] | Ngl Energy Partners Lp [Member]
Business Acquisition [Line Items]
Equity method investment, ownership percentage		11.78%
SemStream [Member] | General Partner [Member] | Additional interest acquired [Member] | Ngl Energy Partners Lp [Member]
Business Acquisition [Line Items]
Equity method investment, ownership percentage									5.36%

Disposals_of_LongLived_Assets_1

Disposals of Long-Lived Assets (Details) (USD $)	1 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2010	Dec. 31, 2012
Crude [Member] | White Cliffs Pipeline, LLC [Member]
Gain (loss) on deconsolidation, pre-tax	($6,800)
SemStream [Member] | SemStream Arizona Residential Propane Business [Member]
Gain (loss) on disposal of discontinued operation, pre-tax		3,090
Loss (gain) on impairment or disposal of long-lived assets, net [Member] | Crude [Member] | White Cliffs Pipeline, LLC [Member]
Gain (loss) on deconsolidation, pre-tax		3,500
Loss (gain) on impairment or disposal of long-lived assets, net [Member] | SemStream [Member] | SemStream Arizona Residential Propane Business [Member]
Gain (loss) on disposal of discontinued operation, pre-tax		$3,090

Disposals_of_LongLived_Assets_2

Disposals of Long-Lived Assets (Details Textual) (USD $)	12 Months Ended			1 Months Ended	0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2010	Jun. 02, 2014	Jun. 01, 2014
Cash proceeds from divestiture	$0	$0	$12,250,000
Corporate and other [Member]
Impairment of Leasehold	11,900,000
Crude [Member] | White Cliffs Pipeline, LLC [Member]
Gain (loss) on deconsolidation, pre-tax				-6,800,000
Eastern Oklahoma gas gathering assets [Member] | SemGas [Member]
Proceeds from sale of property, plant and equipment					2,400,000
Disposal group, including discontinued operation, property, plant and equipment						22,500,000
Residential Division [Member] | SemStream [Member]
Disposal group, including discontinued operation, property, plant and equipment			9,400,000
Gain (loss) on disposal of discontinued operation, pre-tax			3,090,000
Cash proceeds from divestiture			12,300,000
Loss (gain) on impairment or disposal of long-lived assets, net [Member] | Crude [Member] | White Cliffs Pipeline, LLC [Member]
Gain (loss) on deconsolidation, pre-tax			3,500,000
Loss (gain) on impairment or disposal of long-lived assets, net [Member] | Eastern Oklahoma gas gathering assets [Member] | SemGas [Member]
Gain (loss) on disposal					-20,100,000
Loss (gain) on impairment or disposal of long-lived assets, net [Member] | Residential Division [Member] | SemStream [Member]
Gain (loss) on disposal of discontinued operation, pre-tax			$3,090,000

Discontinued_Operations_Detail

Discontinued Operations (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income (loss) from discontinued operations, net of income taxes	$4	$0	$0	($5)	($6)	($2)	$35	$32	($1)	$59	$2,939
Discontinued Operations [Member]
External revenue									0	0	13,518
Gain (loss) on disposal of discontinued operation, pre-tax									0	0	3,090
Income (loss) from discontinued operations before income taxes									-1	59	2,935
Income tax expense									0	0	-4
Income (loss) from discontinued operations, net of income taxes									-1	59	2,939
SemStream [Member] | SemStream Arizona Residential Propane Business [Member]
Gain (loss) on disposal of discontinued operation, pre-tax											$3,090

Segments_Details

Segments (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information
Revenue	$547,237	$594,235	$482,224	$498,883	$457,328	$357,748	$324,244	$287,696	$2,122,579	$1,427,016	$1,237,497
Costs of products sold, exclusive of depreciation and amortization shown below									1,623,358	1,020,100	874,885
Operating									246,613	223,585	224,700
General and administrative									87,845	78,597	71,918
Depreciation and amortization									98,397	66,409	48,210
Loss (gain) on disposal or impairment of long-lived assets, net	11,959	1,376	19,315	-58	-109	408	-376	-162	32,592	-239	-3,531
Total expenses	542,109	577,312	491,178	478,206	448,687	345,387	311,727	282,651	2,088,805	1,388,452	1,216,182
Earnings from equity method investments	15,827	14,223	19,187	14,962	12,788	7,483	14,861	17,345	64,199	52,477	36,036
Gain on issuance of common units by equity method investee	2,121	18,772	0	8,127	26,873	0	0	0	29,020	26,873	0
Operating income (loss)	23,076	49,918	10,233	43,766	48,302	19,844	27,378	22,390	126,993	117,914	57,351
Interest expense (income)									49,044	25,142	8,902
Other expense (income), net									-20,622	44,273	21,569
Total other expenses, net	-2,196	-6,368	29,489	7,497	17,646	13,294	10,613	27,862	28,422	69,415	30,471
Income (loss) from continuing operations before income taxes	25,272	56,286	-19,256	36,269	30,656	6,550	16,765	-5,472	98,571	48,499	26,880
Additions to long-lived assets									343,164	229,318	121,255
Total assets	2,589,802				2,470,614				2,589,802	2,470,614
Equity method investments	577,920				565,124				577,920	565,124
SemStream [Member]
Segment Reporting Information
Revenue									0	0	7
Costs of products sold, exclusive of depreciation and amortization shown below									0	0	33
Operating									0	1	-37
General and administrative									83	600	930
Depreciation and amortization									0	0	0
Loss (gain) on disposal or impairment of long-lived assets, net									0	6	214
Total expenses									83	607	1,140
Earnings from equity method investments									2,343	7,123	-403
Gain on issuance of common units by equity method investee									29,020	26,873
Operating income (loss)									31,280	33,389	-1,536
Interest expense (income)									-5,140	-4,810	-3,449
Other expense (income), net									-34,212	128	-21
Total other expenses, net									-39,352	-4,682	-3,470
Income (loss) from continuing operations before income taxes									70,632	38,071	1,934
Additions to long-lived assets									0	0	0
Total assets	162,246				208,847				162,246	208,847
Equity method investments	162,246				208,848				162,246	208,848
SemCAMS [Member]
Segment Reporting Information
Revenue									176,724	198,450	223,219
Costs of products sold, exclusive of depreciation and amortization shown below									344	305	768
Operating									114,587	150,319	174,284
General and administrative									17,417	14,940	14,020
Depreciation and amortization									14,295	10,766	10,589
Loss (gain) on disposal or impairment of long-lived assets, net									-950	0	0
Total expenses									145,693	176,330	199,661
Earnings from equity method investments									0	0	0
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									31,031	22,120	23,558
Interest expense (income)									13,558	18,928	18,727
Other expense (income), net									20	-20	14
Total other expenses, net									13,578	18,908	18,741
Income (loss) from continuing operations before income taxes									17,453	3,212	4,817
Additions to long-lived assets									35,286	56,122	13,340
Total assets	279,191				306,001				279,191	306,001
Equity method investments	0				0				0	0
SemGas [Member]
Segment Reporting Information
Revenue									380,183	231,119	127,870
Costs of products sold, exclusive of depreciation and amortization shown below									276,852	169,800	100,677
Operating									32,296	20,200	12,712
General and administrative									9,228	7,971	6,195
Depreciation and amortization									26,353	14,517	7,043
Loss (gain) on disposal or impairment of long-lived assets, net									20,092	665	46
Total expenses									364,821	213,153	126,673
Earnings from equity method investments									0	0	0
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									15,362	17,966	1,197
Interest expense (income)									8,570	3,268	1,461
Other expense (income), net									0	-3	0
Total other expenses, net									8,570	3,265	1,461
Income (loss) from continuing operations before income taxes									6,792	14,701	-264
Additions to long-lived assets									166,207	97,021	47,140
Total assets	662,223				552,095				662,223	552,095
Equity method investments	0				0				0	0
SemLogistics [Member]
Segment Reporting Information
Revenue									12,650	11,671	12,341
Costs of products sold, exclusive of depreciation and amortization shown below									615	380	196
Operating									8,361	7,444	5,921
General and administrative									6,139	5,854	5,652
Depreciation and amortization									10,005	9,426	9,780
Loss (gain) on disposal or impairment of long-lived assets, net									-2,490	0	0
Total expenses									22,630	23,104	21,549
Earnings from equity method investments									0	0	0
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									-9,980	-11,433	-9,208
Interest expense (income)									1,528	1,435	2,486
Other expense (income), net									796	-400	-420
Total other expenses, net									2,324	1,035	2,066
Income (loss) from continuing operations before income taxes									-12,304	-12,468	-11,274
Additions to long-lived assets									2,974	2,071	1,188
Total assets	150,498				168,835				150,498	168,835
Equity method investments	0				0				0	0
SemMexico [Member]
Segment Reporting Information
Revenue									290,869	242,559	263,870
Costs of products sold, exclusive of depreciation and amortization shown below									252,082	209,841	236,851
Operating									10,576	9,379	7,677
General and administrative									12,125	10,700	9,433
Depreciation and amortization									6,031	5,991	6,171
Loss (gain) on disposal or impairment of long-lived assets, net									-53	-854	-290
Total expenses									280,761	235,057	259,842
Earnings from equity method investments									0	0	0
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									10,108	7,502	4,028
Interest expense (income)									166	188	314
Other expense (income), net									-11	-652	-38
Total other expenses, net									155	-464	276
Income (loss) from continuing operations before income taxes									9,953	7,966	3,752
Additions to long-lived assets									9,690	6,375	3,396
Total assets	107,225				104,154				107,225	104,154
Equity method investments	0				0				0	0
Corporate and other [Member]
Segment Reporting Information
Revenue									-37,897	-23,985	-10,607
Costs of products sold, exclusive of depreciation and amortization shown below									-37,897	-23,985	-10,606
Operating									0	0	0
General and administrative									22,502	21,766	22,367
Depreciation and amortization									1,678	2,001	2,496
Loss (gain) on disposal or impairment of long-lived assets, net									15,674	0	0
Total expenses									1,957	-218	14,257
Earnings from equity method investments									0	0	0
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									-39,854	-23,767	-24,864
Interest expense (income)									-710	-8,790	-10,228
Other expense (income), net									12,306	45,234	22,003
Total other expenses, net									11,596	36,444	11,775
Income (loss) from continuing operations before income taxes									-51,450	-60,211	-36,639
Additions to long-lived assets									1,672	734	14,827
Total assets	69,780				60,198				69,780	60,198
Equity method investments	0				0				0	0
Crude [Member]
Segment Reporting Information
Revenue									1,300,050	767,202	620,797
Costs of products sold, exclusive of depreciation and amortization shown below									1,131,362	663,759	546,966
Operating									80,793	36,242	24,143
General and administrative									20,351	16,766	13,321
Depreciation and amortization									40,035	23,708	12,131
Loss (gain) on disposal or impairment of long-lived assets, net									319	-56	-3,501
Total expenses									1,272,860	740,419	593,060
Earnings from equity method investments									61,856	45,354	36,439
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									89,046	72,137	64,176
Interest expense (income)									31,072	14,923	-409
Other expense (income), net									479	-14	31
Total other expenses, net									31,551	14,909	-378
Income (loss) from continuing operations before income taxes									57,495	57,228	64,554
Additions to long-lived assets									127,335	66,995	41,364
Total assets	1,158,639				1,070,484				1,158,639	1,070,484
Equity method investments	415,674				356,276				415,674	356,276
Operating Segments [Member]
Segment Reporting Information
Revenue									2,122,579	1,427,016	1,237,497
Operating Segments [Member] | SemStream [Member]
Segment Reporting Information
Revenue									0	0	7
Operating Segments [Member] | SemCAMS [Member]
Segment Reporting Information
Revenue									176,724	198,450	223,219
Operating Segments [Member] | SemGas [Member]
Segment Reporting Information
Revenue									342,286	207,134	117,264
Operating Segments [Member] | SemLogistics [Member]
Segment Reporting Information
Revenue									12,650	11,671	12,341
Operating Segments [Member] | SemMexico [Member]
Segment Reporting Information
Revenue									290,869	242,559	263,870
Operating Segments [Member] | Corporate and other [Member]
Segment Reporting Information
Revenue									0	0	-1
Operating Segments [Member] | Crude [Member]
Segment Reporting Information
Revenue									1,300,050	767,202	620,797
Intersegment Eliminations [Member]
Segment Reporting Information
Revenue									0	0	0
Intersegment Eliminations [Member] | SemStream [Member]
Segment Reporting Information
Revenue									0	0	0
Intersegment Eliminations [Member] | SemCAMS [Member]
Segment Reporting Information
Revenue									0	0	0
Intersegment Eliminations [Member] | SemGas [Member]
Segment Reporting Information
Revenue									37,897	23,985	10,606
Intersegment Eliminations [Member] | SemLogistics [Member]
Segment Reporting Information
Revenue									0	0	0
Intersegment Eliminations [Member] | SemMexico [Member]
Segment Reporting Information
Revenue									0	0	0
Intersegment Eliminations [Member] | Corporate and other [Member]
Segment Reporting Information
Revenue									-37,897	-23,985	-10,606
Intersegment Eliminations [Member] | Crude [Member]
Segment Reporting Information
Revenue									$0	$0	$0

Segments_Details_1

Segments (Details 1) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Income tax expense (benefit)	$12,569	$24,090	($6,672)	$16,526	$24,051	$3,413	$9,288	($54,006)	$46,513	($17,254)	($2,078)
SemCAMS [Member]
Segment Reporting Information [Line Items]
Income tax expense (benefit)									3,135	6,348	720
SemLogistics [Member]
Segment Reporting Information [Line Items]
Income tax expense (benefit)									-2,231	-5,699	-7,736
SemMexico [Member]
Segment Reporting Information [Line Items]
Income tax expense (benefit)									4,053	2,589	2,285
Corporate and other [Member]
Segment Reporting Information [Line Items]
Income tax expense (benefit)									$41,556	($20,492)	$2,653

Inventories_Details

Inventories (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Crude oil	$26,722	$30,779
Asphalt and other	16,810	13,516
Inventories	$43,532	$44,295

Inventories_Details_Textual

Inventories (Details Textual) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Inventory [Line Items]
Inventory valuation adjustment	$5,667	$0	$0
Crude [Member] | Crude Oil [Member]
Inventory [Line Items]
Inventory valuation adjustment	$5,700

Other_Assets_Details

Other Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other Assets [Abstract]
Other prepaid expenses	$5,989	$5,696
Deferred tax asset	5,897	7,325
Other	8,131	990
Total other current assets	$20,017	$14,011

Other_Assets_Details_1

Other Assets (Details 1) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other Assets [Abstract]
Debt issuance costs, net	$22,203	$17,149	[1]
Deferred tax asset	13,933	2,832
Other	8,250	8,908
Total other noncurrent assets, net	$44,386	$28,889
[1]	* See Note 16 for discussion of debt issuance costs.

Property_Plant_and_Equipment_D

Property, Plant and Equipment (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$1,502,454	$1,294,448
Accumulated depreciation	-245,629	-188,720
Property, plant and equipment, net	1,256,825	1,105,728
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	81,886	72,484
Pipelines and related facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	283,347	312,730
Storage and terminal facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	284,300	281,819
Natural gas gathering and processing facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	606,553	347,962
Linefill [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	26,050	14,701
Trucking equipment and other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	40,392	31,978
Office and other property and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	37,120	33,701
Construction-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$142,806	$199,073

Property_Plant_and_Equipment_D1

Property, Plant and Equipment (Details Textual) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Depreciation	$82.50	$60.40	$46.20
Capitalized interest costs	$1.50	$4.30

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 02, 2013	Aug. 01, 2013
In Thousands, unless otherwise specified
Goodwill [Line Items]
Goodwill	$58,326	$62,021	$9,884	$9,453
Crude [Member]
Goodwill [Line Items]
Goodwill	36,116	28,322
SemGas [Member]
Goodwill [Line Items]
Goodwill	13,052	23,839
SemMexico [Member]
Goodwill [Line Items]
Goodwill	9,158	9,860
Barcas Field Services, LLC [Member] | Crude [Member]
Goodwill [Line Items]
Goodwill					28,234
Mid-America Midstream Gas Services, LLC [Member] | SemGas [Member]
Goodwill [Line Items]
Goodwill						$13,052

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets (Details 1) (USD $)	12 Months Ended			1 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014	Sep. 02, 2013	Aug. 01, 2013	Jun. 23, 2014
Goodwill [Line Items]
Goodwill, Beginning Balance	$62,021	$9,884	$9,453
Currency translation adjustments	-702	-24	431
Goodwill, Ending Balance	58,326	62,021	9,884
Crude [Member]
Goodwill [Line Items]
Goodwill, Ending Balance	36,116	28,322
SemGas [Member]
Goodwill [Line Items]
Goodwill, Ending Balance	13,052	23,839
Barcas Field Services, LLC [Member] | Crude [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance					28,234
Goodwill, Acquired During Period		28,322
Goodwill, Purchase Accounting Adjustments	-98
Goodwill, Ending Balance					28,234
Mid-America Midstream Gas Services, LLC [Member] | SemGas [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance						13,052
Goodwill, Acquired During Period		23,839
Goodwill, Purchase Accounting Adjustments	-10,787			-10,800
Goodwill, Ending Balance						13,052
Chesapeake crude oil trucking assets [Member] | Crude [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance							7,892
Goodwill, Acquired During Period	7,892
Goodwill, Purchase Accounting Adjustments	-10,000
Goodwill, Ending Balance							$7,892

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	$173,065	$174,838	$7,585	$8,950
Crude [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	16,640	5,775
SemGas [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	152,383	163,144
SemMexico [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	4,016	5,888
Corporate and other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	$26	$31

Goodwill_and_Other_Intangible_5

Goodwill and Other Intangible Assets (Details 3) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net, beginning balance	$174,838	$7,585	$8,950
Amortization	-15,875	-6,018	-2,017
Currency translation adjustments	-545	9	652
Finite-Lived Intangible Assets, Net, ending balance	173,065	174,838	7,585
Crude [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net, ending balance	16,640	5,775
SemGas [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net, ending balance	152,383	163,144
Barcas Field Services, LLC [Member] | Crude [Member]
Finite-Lived Intangible Assets [Line Items]
Customer contract intangible asset acquired		6,930
Indefinite-lived Intangible Assets, Purchase Accounting Adjustments	-50
Mid-America Midstream Gas Services, LLC [Member] | SemGas [Member]
Finite-Lived Intangible Assets [Line Items]
Customer contract intangible asset acquired		166,332
Indefinite-lived Intangible Assets, Purchase Accounting Adjustments	-2,313
Chesapeake crude oil trucking assets [Member] | Crude [Member]
Finite-Lived Intangible Assets [Line Items]
Customer contract intangible asset acquired	$17,010

Goodwill_and_Other_Intangible_6

Goodwill and Other Intangible Assets (Details 4) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Goodwill And Other Intangible Assets [Abstract]
For year ending, December 31, 2015	$10,334
For year ending, December 31, 2016	10,928
For year ending, December 31, 2017	11,011
For year ending, December 31, 2018	10,918
For year ending, December 31, 2019	10,317
Thereafter	119,557
Total estimated amortization expense	$173,065	$174,838	$7,585	$8,950

Goodwill_and_Other_Intangible_7

Goodwill and Other Intangible Assets (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 24, 2014	Jun. 23, 2014
Goodwill [Line Items]
Goodwill, Amortization Period for Income Taxes	15 years
Finite-lived intangible assets, net	$173,065,000	$174,838,000	$7,585,000	$8,950,000
NGL Energy [Member]
Goodwill [Line Items]
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	71,400,000
Glass Mountain Pipeline LLC [Member]
Goodwill [Line Items]
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	31,000,000
SemMexico [Member]
Goodwill [Line Items]
Finite-lived intangible assets, net	4,016,000	5,888,000
Crude [Member]
Goodwill [Line Items]
Finite-lived intangible assets, net	16,640,000	5,775,000
Customer Relationships [Member]
Goodwill [Line Items]
Finite-lived intangible assets, net	171,600,000
Unpatented Technology [Member] | SemMexico [Member]
Goodwill [Line Items]
Finite-lived intangible assets, net	1,300,000
Chesapeake crude oil trucking assets [Member] | Crude [Member]
Goodwill [Line Items]
Customer contract intangible asset acquired					$17,000,000	$17,010,000
Chesapeake crude oil trucking assets [Member] | Customer Contracts [Member] | Crude [Member]
Goodwill [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years

Financial_Instruments_and_Conc2

Financial Instruments and Concentrations of Risk (Details) (Commodity Derivatives [Member], Level 1 [Member], USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Commodity Derivatives [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	$3,311		$36
Derivative Asset, Fair Value, Gross Liability	-1,637	[1]	-36	[1]
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	1,674		0
Derivative Liability, Fair Value, Gross Liability	1,637		96
Derivative Liability, Fair Value, Gross Asset	-1,637	[1]	-36	[1]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$0		$60
[1]	Relates primarily to exchange traded futures. Gain and loss positions on multiple contracts are settled net on a daily basis with the exchange.

Financial_Instruments_and_Conc3

Financial Instruments and Concentrations of Risk (Details 2)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	bbl	bbl	bbl
Sales [Member]
Derivative, Nonmonetary Notional Amount, Volume	6,773,000	2,595,000	1,743,000
Purchases [Member]
Derivative, Nonmonetary Notional Amount, Volume	6,477,000	2,575,000	1,636,000

Financial_Instruments_and_Conc4

Financial Instruments and Concentrations of Risk (Details 3) (Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	$1,674	$0
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability	$0	$60

Financial_Instruments_and_Conc5

Financial Instruments and Concentrations of Risk (Details 4) (Commodity Contract [Member], Sales [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commodity Contract [Member] | Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses) from commodity derivatives	$19,305	($1,593)	$149

Financial_Instruments_and_Conc6

Financial Instruments and Concentrations of Risk (Details 5) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Concentration of net assets outside of the U.S.
Cash and cash equivalents	$40,598	$79,351	$80,029	$73,613
Other current assets	20,017	14,011
Total assets	2,589,802	2,470,614
Current liabilities	391,662	499,214
Outside Of United States [Member]
Concentration of net assets outside of the U.S.
Cash and cash equivalents	31,920
Other current assets	109,270
Noncurrent assets	407,900
Total assets	549,090
Current liabilities	71,682
Noncurrent liabilities	95,828
Total liabilities	167,510
Net assets	381,580
CANADA
Concentration of net assets outside of the U.S.
Cash and cash equivalents	17,710
Other current assets	58,271
Noncurrent assets	215,386
Total assets	291,367
Current liabilities	37,713
Noncurrent liabilities	75,977
Total liabilities	113,690
Net assets	177,677
UNITED KINGDOM
Concentration of net assets outside of the U.S.
Cash and cash equivalents	957
Other current assets	1,854
Noncurrent assets	147,687
Total assets	150,498
Current liabilities	1,442
Noncurrent liabilities	18,619
Total liabilities	20,061
Net assets	130,437
MEXICO
Concentration of net assets outside of the U.S.
Cash and cash equivalents	13,253
Other current assets	49,145
Noncurrent assets	44,827
Total assets	107,225
Current liabilities	32,527
Noncurrent liabilities	1,232
Total liabilities	33,759
Net assets	$73,466

Financial_Instruments_and_Conc7

Financial Instruments and Concentrations of Risk (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	employees
Level 2 and level 3 fair value transactions	$0	$0	$0
Margin deposits	800,000	800,000
Derivative Asset, Fair Value, Amount Offset Against Collateral	2,500,000	800,000
Fair Value Adjustment of Warrants	13,423,000	46,433,000	21,310,000
Number of employees	1,080
Unionized Employees Concentration Risk [Member] | Canada And Mexico [Member]
Number of employees	130
Number of employees with contracts expiring in collective bargaining agreements	70
Number of employees with contracts renewing collective bargaining agreements	60
Sales Revenue, Goods, Net [Member] | Crude [Member]
Number of customers	1
Sales Revenue, Goods, Net [Member] | Customer Concentration Risk [Member] | Crude [Member]
Percentage of accounts receivables	36.00%
Cost of Goods, Total [Member] | Crude [Member]
purchases of product	469,000,000
Cost of Goods, Total [Member] | Customer Concentration Risk [Member] | Crude [Member]
Number of Suppliers	1
Percentage of accounts receivables	29.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Crude [Member]
Number of customers	2
Percentage of accounts receivables	34.00%
Warrant [Member] | Fair Value, Inputs, Level 1 [Member]
Warrant liability		$58,100,000
Outside Of United States [Member]
Number of employees	540

Income_Taxes_Details_1

Income Taxes (Details 1) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S.									$39,231	$40,002	$21,498
Foreign									59,340	8,497	5,382
Income (loss) from continuing operations before income taxes	$25,272	$56,286	($19,256)	$36,269	$30,656	$6,550	$16,765	($5,472)	$98,571	$48,499	$26,880

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Expense (Benefit), Continuing Operations, by Jurisdiction [Abstract]
Deferred income tax provision (benefit)									$36,148	($36,274)	($11,818)
Provision (benefit) for income taxes	12,569	24,090	-6,672	16,526	24,051	3,413	9,288	-54,006	46,513	-17,254	-2,078
Continuing Operations [Member]
Income Tax Expense (Benefit), Continuing Operations, by Jurisdiction [Abstract]
Foreign									10,430	15,546	9,662
U.S. federal									-195	2,067	0
U.S. state									132	1,435	74
Current income tax provision (benefit)									10,367	19,048	9,736
Foreign									2,024	-10,222	-12,070
U.S. federal									30,074	-23,756	222
U.S. state									4,048	-2,324	34
Deferred income tax provision (benefit)									36,146	-36,302	-11,814
Provision (benefit) for income taxes									$46,513	($17,254)	($2,078)

Income_Taxes_Details_3

Income Taxes (Details 3) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Income (loss) from continuing operations before income taxes	$25,272	$56,286	($19,256)	$36,269	$30,656	$6,550	$16,765	($5,472)	$98,571	$48,499	$26,880
U.S. federal statutory rate									35.00%	35.00%	35.00%
Provision at statutory rate									34,500	16,975	9,408
State income taxes—net of federal benefit									3,197	-577	71
Effect of rates other than statutory									-1,925	-1,041	-829
Effect of U.S. taxation on foreign branches									20,769	2,974	1,883
Foreign tax adjustment, prior years									-3,669	4,533	0
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount									4,698	24,625	0
Noncontrolling interest									7,986	6,096	3,429
Foreign tax credit and offset to branch deferreds									6,851	-2,876	-12,360
Impact of valuation allowance on deferred tax assets									-7,331	-53,218	6,233
Foreign net gain on subsidiary dissolution and intercompany debt waivers									-13,620	0	0
Foreign withholding taxes									5,054	0	0
Other, net									5,975	-2,553	-3,055
Provision (benefit) for income taxes	$12,569	$24,090	($6,672)	$16,526	$24,051	$3,413	$9,288	($54,006)	$46,513	($17,254)	($2,078)

Income_Taxes_Details_4

Income Taxes (Details 4) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Components of Deferred Tax Assets [Abstract]
Net operating loss and other credit carryforwards	$38,835	$9,498
Compensation and benefits	10,736	7,991
Inventories	280	118
Intangible assets	43,977	44,444
Pension plan	3,733	2,849
Allowance for doubtful accounts	1,860	2,140
Deferred revenue	7,622	5,910
Foreign tax credit and offset to branch deferreds	102,286	95,435
Other	17,786	8,243
less: valuation allowance	-102,769	-95,438
Net deferred tax assets	124,346	81,190
Components of Deferred Tax Liabilities [Abstract]
Intangible assets	-5,770	-6,927
Prepaid expenses	-163	-153
Property, plant and equipment	-178,505	-113,030
Equity Investment in partnerships	-78,813	-49,720
Other	-2,549	-1,471
Total deferred tax liabilities	-265,800	-171,301
Net deferred tax assets (liabilities)	($141,454)	($90,111)

Income_Taxes_Details_Textual

Income Taxes (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Foreign withholding taxes	$5,054,000	$0	$0
Federal net operating loss	82,200,000
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	67,200,000
U.S. Capital losses	23,900,000
Forgein income tax credits	55,000,000
Change in valuation allowance	7,300,000
Foreign tax credits and offset to branch deferreds [Member]
Operating Loss Carryforwards [Line Items]
Change in valuation allowance	6,800,000
State net operating loss carryfowards [Member]
Operating Loss Carryforwards [Line Items]
Change in valuation allowance	$500,000

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jun. 14, 2013	Jul. 02, 2014
Debt Instrument [Line Items]
Senior notes	$300,000,000
Capital leases	132,000	125,000
Total long-term debt	767,132,000	615,125,000
less: current portion of long-term debt	40,000	37,000
Noncurrent portion of long-term debt	767,092,000	615,088,000
Corporate Segment [Member]
Debt Instrument [Line Items]
Senior notes	300,000,000	300,000,000	300,000,000
Revolving Credit Facility [Member] | Corporate Segment [Member]
Debt Instrument [Line Items]
Borrowings	35,000,000	70,000,000
Revolving Credit Facility [Member] | SemMexico [Member]
Debt Instrument [Line Items]
Borrowings	0	0
Total long-term debt	0
Rose Rock Midstream L P [Member]
Debt Instrument [Line Items]
Senior notes	400,000,000	0		400,000,000
Noncurrent portion of long-term debt	432,092,000	245,088,000
Rose Rock Midstream L P [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Borrowings	$32,000,000	$245,000,000

LongTerm_Debt_Details_1

Long-Term Debt (Details 1) (Corporate Segment [Member], Senior Notes [Member])	12 Months Ended
	Dec. 31, 2014
Debt Instrument, Redemption, Period One [Member]
Debt Instrument, Redemption [Line Items]
Early redemption premium	105.63%
Debt Instrument, Redemption, Period Two [Member]
Debt Instrument, Redemption [Line Items]
Early redemption premium	103.75%
Debt Instrument, Redemption, Period Three [Member]
Debt Instrument, Redemption [Line Items]
Early redemption premium	101.88%
Debt Instrument, Redemption, Period Four [Member]
Debt Instrument, Redemption [Line Items]
Early redemption premium	100.00%

LongTerm_Debt_Details_2

Long-Term Debt (Details 2) (Rose Rock Midstream L P [Member], Senior Notes [Member])	12 Months Ended
	Dec. 31, 2014
Debt Instrument, Redemption, Period One [Member]
Debt Instrument [Line Items]
Early redemption premium	104.22%
Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Early redemption premium	102.81%
Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Early redemption premium	101.41%
Debt Instrument, Redemption, Period Four [Member]
Debt Instrument [Line Items]
Early redemption premium	100.00%

LongTerm_Debt_Details_3

Long-Term Debt (Details 3) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Scheduled principal payments in the next twelve months	$40
Scheduled principal payments, year two	40
Scheduled principal payments, year three	26
Scheduled principal payments, year four	67,026
Scheduled principal payments, year five	0
Scheduled principal payments, thereafter	700,000
Total long-term debt	767,132	615,125
Senior Notes [Member]
Debt Instrument [Line Items]
Scheduled principal payments in the next twelve months	0
Scheduled principal payments, year two	0
Scheduled principal payments, year three	0
Scheduled principal payments, year four	0
Scheduled principal payments, year five	0
Scheduled principal payments, thereafter	300,000
Total long-term debt	300,000
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Scheduled principal payments in the next twelve months	40
Scheduled principal payments, year two	40
Scheduled principal payments, year three	26
Scheduled principal payments, year four	26
Scheduled principal payments, year five	0
Scheduled principal payments, thereafter	0
Total long-term debt	132
Corporate and other [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Scheduled principal payments in the next twelve months	0
Scheduled principal payments, year two	0
Scheduled principal payments, year three	0
Scheduled principal payments, year four	35,000
Scheduled principal payments, year five	0
Scheduled principal payments, thereafter	0
Total long-term debt	35,000
Crude [Member] | Rose Rock Midstream L P [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Scheduled principal payments in the next twelve months	0
Scheduled principal payments, year two	0
Scheduled principal payments, year three	0
Scheduled principal payments, year four	0
Scheduled principal payments, year five	0
Scheduled principal payments, thereafter	400,000
Total long-term debt	400,000
Crude [Member] | Rose Rock Midstream L P [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Scheduled principal payments in the next twelve months	0
Scheduled principal payments, year two	0
Scheduled principal payments, year three	0
Scheduled principal payments, year four	32,000
Scheduled principal payments, year five	0
Scheduled principal payments, thereafter	0
Total long-term debt	32,000
SemMexico [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Scheduled principal payments in the next twelve months	0
Scheduled principal payments, year two	0
Scheduled principal payments, year three	0
Scheduled principal payments, year four	0
Scheduled principal payments, year five	0
Scheduled principal payments, thereafter	0
Total long-term debt	$0

LongTerm_Debt_Details_Textual

Long-Term Debt (Details Textual)

Dec. 31, 2014

Jul. 02, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Mar. 31, 2014

Dec. 31, 2014

Dec. 31, 2013

Jun. 14, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

USD ($)

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Senior Notes [Member]

Debt issuance [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

SemMexico [Member]

Level 1 [Member]

Level 1 [Member]

Redemption prior to June 15, 2016 [Member]

Redemption prior to June 15, 2016 [Member]

Redemption prior to June 15, 2016 [Member]

Redemption prior to June 15, 2016 [Member]

Redemption prior to June 15, 2016 [Member]

Redemption prior to June 15, 2016 [Member]

Eurodollar [Member]

Eurodollar [Member]

Eurodollar [Member]

Eurodollar [Member]

Base Rate [Member]

Base Rate [Member]

Base Rate [Member]

Base Rate [Member]

Mexican bank prime rate [Member]

Mexican bank prime rate [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

Other Noncurrent Assets [Member]

USD ($)

USD ($)

USD ($)

Senior Notes [Member]

Bilateral Letter of Credit [Member]

Minimum [Member]

Maximum [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Maximum net debt to EBITDA ratio [Member]

Maximum senior secured debt to EBITDA ratio [Member]

Minimum EBITDA to interest expense ratio [Member]

Rose Rock Midstream L P [Member]

USD ($)

USD ($)

USD ($)

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Letter of Credit [Member]

Senior Notes [Member]

Senior Notes [Member]

USD ($)

USD ($)

USD ($)

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

USD denominated letter of credit [Member]

Revolving credit facility 2 [Member]

Revolving credit facility 2 [Member]

Senior Notes [Member]

Corporate Segment [Member]

Rose Rock Midstream L P [Member]

Sale of stock [Member]

Change of control [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Corporate Segment [Member]

Corporate Segment [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Corporate Segment [Member]

Corporate Segment [Member]

SemMexico [Member]

SemMexico [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Corporate Segment [Member]

Corporate Segment [Member]

USD ($)

USD ($)

Letter of Credit [Member]

Letter of Credit [Member]

USD ($)

USD ($)

USD ($)

Alternate Base Rate Borrowings [Member]

Letter of Credit [Member]

Eurodollar Rate Borrowings [Member]

Minimum [Member]

Maximum [Member]

Subordinated Debt [Member]

USD ($)

USD ($)

USD ($)

Alternate Base Rate Borrowings [Member]

Eurodollar [Member]

Minimum [Member]

Maximum [Member]

USD ($)

USD ($)

USD ($)

USD ($)

MXN

USD ($)

Letter of Credit [Member]

Letter of Credit [Member]

Minimum [Member]

Maximum [Member]

USD ($)

USD ($)

MXN

Rose Rock Midstream L P [Member]

Senior Notes [Member]

Senior Notes [Member]

Rose Rock Midstream L P [Member]

Rose Rock Midstream L P [Member]

Senior Notes [Member]

Sale of stock [Member]

Change of control [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Line of Credit [Member]

Revolving credit facility 2 [Member]

Senior Notes [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Senior Notes [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

MXN

Letter of Credit [Member]

Letter of Credit [Member]

USD ($)

USD ($)

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

USD ($)

USD ($)

USD ($)

USD ($)

Long Term Debt (Textual) [Abstract]

Senior notes

$300,000,000

$400,000,000

$400,000,000

$0

$300,000,000

$300,000,000

$300,000,000

Debt instrument, interest rate stated percentage

5.63%

7.50%

7.50%

Proceeds from Issuance of Senior Long-term Debt

391,900,000

294,000,000

Senior Notes Redemable Prior to June 15, 2016

35.00%

Senior Notes Redemable Prior to July15, 2017

35.00%

Early redemption premium

1.00%

105.63%

101.00%

1.00%

107.50%

101.00%

Basis point adjustment to discount rate

50

50

Interest expense recorded

11,700,000

9,000,000

8,700,000

1,900,000

6,300,000

7,700,000

6,900,000

23,300,000

12,700,000

200,000

200,000

400,000

Deferred Finance Costs, Noncurrent, Net

8,000,000

3,800,000

5,000,000

5,400,000

Maximum borrowing capacity

585,000,000

150,000,000

500,000,000

250,000,000

3,000,000

44,000,000

3,800,000

56,000,000

Borrowings outstanding

32,000,000

245,000,000

12,000,000

20,000,000

35,000,000

70,000,000

15,000,000

20,000,000

0

0

0

Letters of credit outstanding

67,600,000

17,500,000

3,800,000

19,800,000

292,800,000

3,000,000

Line of Credit Facility, Maximum Borrowing Incremental Increases

200,000,000

300,000,000

Minimum aggregate issuance to elect alternative financial covenants

200,000,000

Debt Instrument, Basis Spread on Variable Rate

1.75%

3.00%

2.00%

3.25%

0.75%

2.00%

1.00%

2.25%

1.50%

1.50%

Interest rate in effect

1.75%

2.50%

2.00%

4.25%

2.23%

2.00%

3.25%

0.40%

0.70%

Percentage of line of credit facility fronting fee

0.25%

0.25%

Commitment fee on unused capacity

0.38%

0.50%

0.38%

0.50%

Debt Instrument Annual Administrative Fee

100,000

100,000

Line of Credit Facility, Covenant Terms

5.5

3.5

2.5

Effective interest rate

4.75%

2.74%

Line of Credit Facility, Interest Rate During Period

1.75%

3.00%

Long-term Debt, Fair Value

$368,000,000

$299,000,000

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$41,185	$40,105	$35,886
Accretion	4,807	4,752	4,554
Payments made	-514	-808	-1,169
Currency translation adjustments	-3,524	-2,864	834
Ending Balance	$41,954	$41,185	$40,105

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 1) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
Operating Leases, Due next twelve months	$9,464
Operating Leases, Due in Two Years	9,181
Operating Leases, Due in Three Years	6,737
Operating Leases, Due in Four Years	2,997
Operating Leases, Due in Five Years	1,826
Operating Leases, Thereafter	6,967
Operating Leases, Total future minimum lease payments	$37,172

Commitments_and_Contingencies_3

Commitments and Contingencies (Details 2) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified	bbl
Fixed Price Sales [Member]
Summary Of Purchase And Sale Commitments
Sale commitments, Volume (barrels)	13,612,000
Sale commitments, Value	$1,152,966
Floating Price Sales [Member]
Summary Of Purchase And Sale Commitments
Sale commitments, Volume (barrels)	10,719,000
Sale commitments, Value	445,655
Fixed Price Purchases [Member]
Summary Of Purchase And Sale Commitments
Purchase commitments, Volume (barrels)	13,648,000
Purchase commitments, Value	1,141,694
Floating Price Purchases [Member]
Summary Of Purchase And Sale Commitments
Purchase commitments, Volume (barrels)	7,187,000
Purchase commitments, Value	$373,539

Commitments_and_Contingencies_4

Commitments and Contingencies (Details 3) (Fractionation capacity [Member], USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Fractionation capacity [Member]
Long-term Purchase Commitment [Line Items]
Purchase Obligation, Due in Next Twelve Months	$10,199
Purchase Obligation, Due in Second Year	11,804
Purchase Obligation, Due in Third Year	11,938
Purchase Obligation, Due in Fourth Year	10,060
Purchase Obligation, Due in Fifth Year	9,121
Purchase Obligation, Due after Fifth Year	24,391
Purchase Obligation	$77,513

Commitments_and_Contingencies_5

Commitments and Contingencies (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 11, 2013	Aug. 18, 2011
	sites			bbl	bbl
Commitments and Contingencies (Textual) [Abstract]
Site contingency number of sites checked	6
Number of sites appearing to have soil contamination	4
Number of sites requiring remediation and water contamination as per phase two investigations	4
Number of sites closed	1
Sites for which closure is anticipated in 2015	3
Site contingency, number of sites remaining open	5
Estimated cost to retire facilities	$93,400,000
Asset retirement obligation additional estimated costs attributable to third-party owners'	37,700,000
Operating leases, rent expense	16,200,000	11,400,000	8,400,000
Accrued liabilities	92,694,000	83,429,000
SemGas [Member]
Commitments and Contingencies (Textual) [Abstract]
Site contingency number of sites checked	1
Crude [Member]
Commitments and Contingencies (Textual) [Abstract]
Site contingency number of sites checked	5
Minimum [Member]
Commitments and Contingencies (Textual) [Abstract]
Notice required to cancel purchase agreements, days	30 days
Maximum [Member]
Commitments and Contingencies (Textual) [Abstract]
Notice required to cancel purchase agreements, days	120 days
Crude [Member]
Commitments and Contingencies (Textual) [Abstract]
Loss contingency claims, number of barrels of crude oil claimed to be owed					141,000
Barrels of crude oil determined to be missing				148,000
Commitments [Member] | SemGas [Member]
Commitments and Contingencies (Textual) [Abstract]
Accrued liabilities	25,800
Pipeline transportation capacity [Member] | SemGas [Member]
Commitments and Contingencies (Textual) [Abstract]
Unrecorded Unconditional Purchase Obligation	$2,600,000

Equity_Details

Equity (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Schedule of Common Stock
Total shares	44,689,000		42,898,000
Common Stock, Shares, Outstanding	43,614,054
Stock Issued During Period, Shares, Employee Stock Purchase Plans	6,999
Par value per share	$0.01		$0.01
Common stock on balance sheet	$436		$425
Shares paid for tax withholding	11,120
Shares issued on Emergence Date [Member]
Schedule of Common Stock
Total shares	40,882,496
Shares subsequently issued in settlement of pre-petition claims [Member]
Schedule of Common Stock
Total shares	517,500
Issuance of shares under employee and director compensation programs [Member]
Schedule of Common Stock
Total shares	861,503	[1]
Awards vested, shares	169,340
Shares issued upon exercise of warrants [Member]
Schedule of Common Stock
Total shares	1,345,556	[2]
[1]	* These shares include 169,340 shares which vested during the year ended December 31, 2014. Of these vested shares, recipients sold back to the Company 11,120 shares to satisfy tax withholding obligations which are being recognized at cost as treasury stock on the consolidated balance sheet.
[2]	** These shares include 904,231 shares issued during the year ended December 31, 2014.

Equity_Details_1

Equity (Details 1) (Warrants issued on emergence date [Member])	Dec. 31, 2014
Warrants issued on emergence date [Member]
Warrants and Rights Note Disclosure [Abstract]
Total warrants	1,634,210

Equity_Equity_Details_2

Equity Equity (Details 2) (USD $)	0 Months Ended		1 Months Ended	0 Months Ended	1 Months Ended			12 Months Ended	0 Months Ended
	Nov. 28, 2014	Aug. 29, 2014	19-May-14	Mar. 10, 2014	Nov. 22, 2013	Aug. 19, 2013	30-May-13	Dec. 31, 2014	Mar. 20, 2015
Dividends paid	$0.30	$0.27	$0.24	$0.22	$0.21	$0.20	$0.19
Dividends Payable, Date to be Paid	28-Nov-14	28-Aug-14	29-May-14	20-Mar-14	3-Dec-13	30-Aug-13	30-May-13
Second quarter 2013 dividend [Member]
Dividends, date declared								8-May-13
Dividends, date of record								20-May-13
Third quarter 2013 dividend [Member]
Dividends, date declared								8-Aug-13
Dividends, date of record								19-Aug-13
Fourth quarter 2013 dividend [Member]
Dividends, date declared								11-Nov-13
Dividends, date of record								22-Nov-13
First quarter 2014 dividend [Member]
Dividends, date declared								25-Feb-14
Dividends, date of record								10-Mar-14
Second quarter 2014 dividend [Member] [Member]
Dividends, date declared								8-May-14
Dividends, date of record								19-May-14
Third quarter 2014 dividend [Member]
Dividends, date declared								6-Aug-14
Dividends, date of record								18-Aug-14
Fourth quarter 2014 dividend [Member]
Dividends, date declared								6-Nov-14
Dividends, date of record								17-Nov-14
First quarter 2015 dividend [Member]
Dividends, date declared								26-Feb-15
Dividends, date of record								9-Mar-15
Subsequent Event [Member]
Dividends Payable, Date to be Paid									20-Mar-15
Common Stock, Dividends, Per Share, Declared									$0.34

Equity_Details_Textual

Equity (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Equity [Line Items]
Common stock shares issued	44,689,000		42,898,000
Number of shares to be issued in settlement of pre-petition claims	517,500
Common stock shares authorized	100,000,000		100,000,000
Additional warrants issued in settlement of pre-petition claims	544,737
Par value per share	0.01		0.01
Price of purchase of one share of common stock against warrant	25
Common Stock, Shares, Outstanding	43,614,054
Warrants issued on emergence date [Member]
Equity [Line Items]
Warrants issued	1,634,210
Class A [Member]
Equity [Line Items]
Common stock shares authorized	90,000,000
Class B [Member]
Equity [Line Items]
Common stock shares authorized	10,000,000
Par value per share	0.01
Common Stock, Shares, Outstanding			28,235
Shares issued upon exercise of warrants [Member]
Equity [Line Items]
Stock issued from warrant exercises, shares	904,231		425,618
Common stock shares issued	1,345,556	[1]
Class of warrant, number exercised	1,271,983
Shares issued on Emergence Date [Member]
Equity [Line Items]
Common stock shares issued	40,882,496
Shares subsequently issued in settlement of pre-petition claims [Member]
Equity [Line Items]
Common stock shares issued	517,500
[1]	** These shares include 904,231 shares issued during the year ended December 31, 2014.

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent									$52,058	$65,753	$28,958
Basic earnings per share
Net income (loss)	12,707	32,196	-12,584	19,738	6,599	3,135	7,512	48,566	52,057	65,812	31,897
Income (loss) from discontinued operations, net of income taxes	4	0	0	-5	-6	-2	35	32	-1	59	2,939
less: Income attributable to noncontrolling interest	4,633	6,934	5,025	6,150	3,319	5,054	3,943	5,143	22,817	17,710	9,797
Net Income (Loss) Available to Common Stockholders, Basic									29,240	48,102	22,100
Weighted average common stock outstanding									42,665	42,339	41,939
Basic earnings (loss) per share, net	$0.19	$0.59	($0.41)	$0.32	$0.08	($0.05)	$0.08	$1.03	$0.69	$1.14	$0.53
Continuing Operations [Member]
Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent									52,058	65,753	28,958
Basic earnings per share
less: Income attributable to noncontrolling interest									22,817	17,710	9,797
Net Income (Loss) Available to Common Stockholders, Basic									29,241	48,043	19,161
Weighted average common stock outstanding									42,665	42,339	41,939
Basic earnings (loss) per share from continuing operations									$0.69	$1.13	$0.46
Discontinued Operations [Member]
Basic earnings per share
Income (loss) from discontinued operations, net of income taxes									-1	59	2,939
less: Income attributable to noncontrolling interest									0	0	0
Net Income (Loss) Available to Common Stockholders, Basic									($1)	$59	$2,939
Weighted average common stock outstanding									42,665	42,339	41,939
Basic earnings (loss) per share from discontinued operations									$0	$0	$0.07

Earnings_Per_Share_Details_1

Earnings Per Share (Details 1) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent									$52,058	$65,753	$28,958
Diluted earnings per share
Net income (loss)	12,707	32,196	-12,584	19,738	6,599	3,135	7,512	48,566	52,057	65,812	31,897
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	4	0	0	-5	-6	-2	35	32	-1	59	2,939
Less: net income attributable to noncontrolling interests	4,633	6,934	5,025	6,150	3,319	5,054	3,943	5,143	22,817	17,710	9,797
Net Income (Loss) Available to Common Stockholders, Diluted									29,240	48,102	22,100
Weighted Average Number of Shares Issued, Basic									42,665	42,339	41,939
Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares									302	307	315
Diluted weighted average common stock outstanding									42,967	42,646	42,254
Earnings Per Share, Diluted	$0.18	$0.59	($0.41)	$0.29	$0.08	($0.05)	$0.08	$1.03	$0.68	$1.13	$0.52
Continuing Operations [Member]
Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent									52,058	65,753	28,958
Diluted earnings per share
Less: net income attributable to noncontrolling interests									22,817	17,710	9,797
Net Income (Loss) Available to Common Stockholders, Diluted									29,241	48,043	19,161
Weighted Average Number of Shares Issued, Basic									42,665	42,339	41,939
Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares									302	307	315
Diluted weighted average common stock outstanding									42,967	42,646	42,254
Income (Loss) from Continuing Operations, Per Diluted Share									$0.68	$1.13	$0.45
Discontinued Operations [Member]
Diluted earnings per share
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									-1	59	2,939
Less: net income attributable to noncontrolling interests									0	0	0
Net Income (Loss) Available to Common Stockholders, Diluted									($1)	$59	$2,939
Weighted Average Number of Shares Issued, Basic									42,665	42,339	41,939
Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares									302	307	315
Diluted weighted average common stock outstanding									42,967	42,646	42,254
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share									$0	$0	$0.07

EquityBased_Compensation_Detai

Equity-Based Compensation (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2015
Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Outstanding, shares	530,603	450,552	410,506
Awards granted, shares	207,786	201,451	246,432
Awards vested, shares	-169,340	-107,988	-162,986
Awards forfeited, shares	-119,130	-13,412	-43,400
Outstanding, shares	449,919	530,603	450,552
Awards outstanding, average grant date fair value	$36.80	$26.87	$26.59
Awards granted, average grant date fair value per share	$77.14	$52.78	$27.81
Awards vested, average grant date fair value per share	$33.07	$25.71	$25.20
Awards forfeited, average grant date fair value per share	$42.16	$32.36	$27.74
Awards outstanding, average grant date fair value	$70.69	$36.80	$26.87
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested	$5,600,000	$2,776,000	$4,107,000
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Awards vested, shares				-102,103

EquityBased_Compensation_Detai1

Equity-Based Compensation (Details 1) (Rose Rock Midstream L P [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Rose Rock Midstream L P [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, shares	82,948	43,960	0
Awards granted, shares	46,536	49,104	46,069
Awards vested, shares	-5,712	-9,333	0
Awards forfeited, shares	-21,432	-783	-2,109
Outstanding, shares	102,340	82,948	43,960
Awards outstanding, average grant date fair value	$28.59	$21.91	$0
Awards granted, average grant date fair value per share	$41.35	$34.41	$21.97
Awards vested, average grant date fair value per share	$35.87	$27.25	$0
Awards forfeited, average grant date fair value per share	$29.82	$34.40	$20.60
Awards outstanding, average grant date fair value	$33.79	$28.59	$21.91
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested	$205,000	$254,000	$0

EquityBased_Compensation_Detai2

Equity-Based Compensation (Details 2)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	29.30%	28.90%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	0.66%	0.35%

EquityBased_Compensation_Detai3

Equity-Based Compensation (Details Textual) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares paid for tax withholding	11,120
Shares issued based on unit distribution rights vested during period	593	0
Value of unvested dividend rights to be settled in Class A shares	$155,000
Number of Class A shares equal to unvested dividend rights	2,263
Equity-based compensation expense recognized	7,300,000	6,500,000	6,200,000
Unrecognized compensation expense for nonvested awards	14,200,000
Weighted average vesting period	18 months
Employee stock purchase plan maximum contribution	10.00%
Employee stock purchase plan discounted price	85.00%
Shares authorized for employee stock purchase plan	1,000,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans	6,999
Share price	$68.39
Percentage of awards assumed will ultimately vest at grant date	100.00%
Percentage of volatility assumption based on historical volatility		50.00%
Percentage of volatility assumption based on implied volatility		50.00%
Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance pursuant to employee and director compensation programs	2,781,635
Awards vested, shares	169,340	107,988	162,986
Cash settled UUD [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested Dividend Equivalent Value	244,000
2014 stock compensation awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation awards which could vest if certain targets are met	54,000
2013 stock compensation awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation awards which could vest if certain targets are met	49,000
2012 stock compensation awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation awards which could vest if certain targets are met	25,000
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vested, shares				102,103
Shares issued based on unit distribution rights vested during period				1,793
Subsequent Event [Member] | Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares paid for tax withholding				36,564
Rose Rock equity incentive plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense recognized	900,000	800,000	300,000
Unrecognized compensation expense for nonvested awards	1,800,000
Weighted average vesting period	19 months
Unvested Unit Distributions Value	129,000
Number Of Common Units Equivalent To Unvested Unit Distributions	2,835
Rose Rock equity incentive plan [Member] | Cash settled UUD [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested Dividend Equivalent Value	$177,000
Rose Rock equity incentive plan [Member] | Distribution equivalent [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vested, shares	0	406
Rose Rock equity incentive plan [Member] | Subsequent Event [Member] | Distribution equivalent [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vested, shares				3,335
Rose Rock Midstream L P [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vested, shares	5,712	9,333	0
General partner ownership interest	2.00%
Share price	$45.45
Rose Rock Midstream L P [Member] | Subsequent Event [Member] | Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vested, shares				25,745
Shares paid for tax withholding				10,537

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	$24,036	$28,357
Service cost	477	577	596
Interest cost	1,080	1,047	1,134
Actuarial (gains) losses	6,228	-3,022
Benefits paid	-521	-968
Currency translation adjustment	-2,034	-1,955
Projected benefit obligation at end of year	29,266	24,036	28,357
Change in fair value of plan assets:
Fair value of plan assets at beginning of year	25,582	22,727
Employer contributions	601	1,144
Actual return on plan assets	2,915	4,397
Benefits paid	-521	-968
Currency translation adjustment	-2,209	-1,718
Fair value of plan assets at end of year	26,368	25,582	22,727
Funded status:	-2,898	1,546
Accumulated benefit obligation at end of year	$26,544	$22,687

Employee_Benefit_Plans_Details1

Employee Benefit Plans (Details 1)	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation discount rate	3.80%	4.70%
Benefit obligation rate of compensation increase	4.50%	3.50%

Employee_Benefit_Plans_Details2

Employee Benefit Plans (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Service cost	$477	$577	$596
Interest cost	1,080	1,047	1,134
Expected return on plan assets	-1,469	-1,298	-1,263
Settlement loss	0	0	-55
Other	-7	186	118
Net periodic benefit cost	$81	$512	$530

Employee_Benefit_Plans_Details3

Employee Benefit Plans (Details 3)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost discount rate	4.70%	3.90%	4.25%
Net periodic benefit costs long-term rate of return on assets	6.00%	6.00%	6.00%
Net periodic benefit cost rate of compensation increase	3.50%	3.50%	3.50%

Employee_Benefit_Plans_Details4

Employee Benefit Plans (Details 4) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Compensation and Retirement Disclosure [Abstract]
Next twelve months	$4,800
Year two	2,809
Year three	2,046
Year four	987
Year five	1,114
Years six through ten	$12,178

Employee_Benefit_Plans_Details5

Employee Benefit Plans (Details 5) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair value of plan assets	$26,368	$25,582	$22,727
Cash and cash equivalents [Member]
Fair value of plan assets	0	171
Actual Allocation	0.00%
Normal Allocation Per Investment Policy	0.00%
Minimum Allocation Per Investment Policy	0.00%
Maximum Allocation Per Investment Policy	10.00%
Pooled Funds-fixed income [Member]
Fair value of plan assets	8,938	8,381
Actual Allocation	33.90%
Normal Allocation Per Investment Policy	40.00%
Minimum Allocation Per Investment Policy	32.50%
Maximum Allocation Per Investment Policy	47.50%
Pooled Funds-Canadian Equities [Member]
Fair value of plan assets	8,828	8,324
Actual Allocation	33.50%
Normal Allocation Per Investment Policy	30.00%
Minimum Allocation Per Investment Policy	22.50%
Maximum Allocation Per Investment Policy	37.50%
Pooled Funds-non-Canadian Equities [Member]
Fair value of plan assets	$8,602	$8,706
Actual Allocation	32.60%
Normal Allocation Per Investment Policy	30.00%
Minimum Allocation Per Investment Policy	22.50%
Maximum Allocation Per Investment Policy	37.50%

Employee_Benefit_Plans_Details6

Employee Benefit Plans (Details 6) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$26,368		$25,582		$22,727
Cash and cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0		171
Equity mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	8,828		8,324
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0		171
Recurring [Member] | Level 1 [Member] | Cash and cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0		171
Recurring [Member] | Level 1 [Member] | Fixed income mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	[1]	0	[1]
Recurring [Member] | Level 1 [Member] | Equity mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	[1]	0	[1]
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	26,368		25,411
Recurring [Member] | Level 2 [Member] | Cash and cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0		0
Recurring [Member] | Level 2 [Member] | Fixed income mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	8,938	[1]	8,381	[1]
Recurring [Member] | Level 2 [Member] | Equity mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	17,430	[1]	17,030	[1]
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0		0
Recurring [Member] | Level 3 [Member] | Cash and cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0		0
Recurring [Member] | Level 3 [Member] | Fixed income mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	[1]	0	[1]
Recurring [Member] | Level 3 [Member] | Equity mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$0	[1]	$0	[1]
[1]	(a) Mutual funds are valued daily in actively traded markets by an independent custodian for the investment manager. For purposes of calculating the value, portfolio securities and other assets for which market quotes are readily available are valued at market value. Market value is generally determined on a basis of last reported sales prices, or if no sales are reported, based on quotes obtained from a quotation reporting system, established market makers, or pricing services. Investments initially valued in currencies other than the U.S. dollar are converted to the U.S. dollar using exchange rates obtained from pricing services.

Employee_Benefit_Plans_Details7

Employee Benefit Plans (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Postretirement Benefits [Line Items]
Contributions to the defined contribution plans	$1,900,000	$1,100,000	$900,000
Funded status of the Pension Plans	-2,898,000	1,546,000
Funded status of the pension plans to other comprehensive income (loss), net of income taxes	-3,700,000	4,800,000	-400,000
Estimated contributions to pension plans	600,000
Projected benefit obligation	29,266,000	24,036,000	28,357,000
Other Noncurrent Liabilities [Member]
Postretirement Benefits [Line Items]
Funded status of the Pension Plans	-2,899,000
Other Noncurrent Assets [Member]
Postretirement Benefits [Line Items]
Funded status of the Pension Plans		1,546,000
Postretirement Health Coverage [Member] | Other Noncurrent Liabilities [Member]
Postretirement Benefits [Line Items]
Projected benefit obligation	$1,700,000	$1,600,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Beginning Balance	($2,854)	($1,299)	($13,875)
Currency translation adjustments	-20,551	-6,363	12,635
Changes related to interest rate swaps net income tax benefits			284
Changes related to benefit plans, net of income tax expense	-3,736	4,808	-343
Ending Balance	-27,141	-2,854	-1,299
Currency Translation [Member]
Beginning Balance	-4,508	1,855	-10,780
Currency translation adjustments	-20,551	-6,363	12,635
Changes related to interest rate swaps net income tax benefits			0
Changes related to benefit plans, net of income tax expense	0	0	0
Ending Balance	-25,059	-4,508	1,855
Employee Benefit Plans [Member]
Beginning Balance	1,654	-3,154	-2,811
Currency translation adjustments	0	0	0
Changes related to interest rate swaps net income tax benefits			0
Changes related to benefit plans, net of income tax expense	3,736	4,808	-343
Ending Balance	-2,082	1,654	-3,154
Interest Rate Swaps [Member]
Beginning Balance	0	0	-284
Currency translation adjustments	0	0	0
Changes related to interest rate swaps net income tax benefits			284
Changes related to benefit plans, net of income tax expense	0	0	0
Ending Balance	$0	$0	$0

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Loss) (Details 1) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes related to benefit plans, income tax expense (benefit)	($1,245)	$1,603	($117)
Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax	($11,102)	($3,999)	$1,168

Supplemental_Cash_Flow_Informa2

Supplemental Cash Flow Information (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of operating assets and liabilities
Decrease (increase) in restricted cash	($2,045)	$29,467	$4,907
Decrease (increase) in accounts receivable	-32,602	11,172	-129,102
Decrease (increase) in receivable from affiliates	50,454	-61,095	230
Decrease (increase) in inventories	-6,243	-11,352	-936
Decrease (increase) in derivatives and margin deposits	28	1,012	-1,245
Decrease (increase) in other current assets	-614	9,361	4,197
Increase (decrease) in other noncurrent assets	-2	-137	-2,467
Increase (decrease) in accounts payable and accrued liabilities	11,461	31,030	114,776
Increase (decrease) in payable to affiliates	-48,819	62,279	-6,871
Increase (decrease) in payables to pre-petition creditors	-54	-29,609	-5,206
Increase (decrease) in other noncurrent liabilities	5,067	-2,541	2,500
Total changes in operating assets and liabilities	($23,365)	$39,861	($14,283)

Supplemental_Cash_Flow_Informa3

Supplemental Cash Flow Information (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Significant Noncash Transactions [Line Items]
Sale of interest in equity investment to related party	$31,930,000	$67,291,000
Tax effect of adjustment to APIC from sale of equity investment to less than wholly owned subsidiary	31,930,000	67,291,000
Proceeds from warrant exercises	1,451,000	225,000	0
Interest Paid	36,700,000	23,900,000	8,000,000
Income taxes (net of refunds received)	23,500,000	13,900,000	11,400,000
Capital Expenditures Incurred but Not yet Paid	7,000,000	10,100,000	1,600,000
Proceeds from Sale of Equity Method Investments	79,741,000	0	0
Noncontrolling Interest [Member]
Other Significant Noncash Transactions [Line Items]
Sale of interest in equity investment to related party	85,173,000	180,220,000
Additional Paid-in Capital [Member]
Other Significant Noncash Transactions [Line Items]
Sale of interest in equity investment to related party	-53,243,000	-112,929,000
Shares issued upon exercise of warrants [Member]
Other Significant Noncash Transactions [Line Items]
Stock issued from warrant exercises, shares	904,231	425,618
Warrant [Member]
Other Significant Noncash Transactions [Line Items]
Increase in additional paid in capital due to warrant exercises	73,000,000	21,400,000
Ngl Energy Partners Lp [Member]
Other Significant Noncash Transactions [Line Items]
Proceeds from Sale of Equity Method Investments	88,800,000
Proceeds from Sale of Equity Method Investments	$79,700,000

Quarterly_Financial_Data_Detai

Quarterly Financial Data (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Abstract]
Total revenues	$547,237	$594,235	$482,224	$498,883	$457,328	$357,748	$324,244	$287,696	$2,122,579	$1,427,016	$1,237,497
Loss (gain) on disposal or impairment of long-lived assets, net	11,959	1,376	19,315	-58	-109	408	-376	-162	32,592	-239	-3,531
Other operating costs and expenses	530,150	575,936	471,863	478,264	448,796	344,979	312,103	282,813	2,056,213	1,388,691
Total expenses	542,109	577,312	491,178	478,206	448,687	345,387	311,727	282,651	2,088,805	1,388,452	1,216,182
Earnings from equity method investments	15,827	14,223	19,187	14,962	12,788	7,483	14,861	17,345	64,199	52,477	36,036
Gain on issuance of common units by equity method investee	2,121	18,772	0	8,127	26,873	0	0	0	29,020	26,873	0
Operating income	23,076	49,918	10,233	43,766	48,302	19,844	27,378	22,390	126,993	117,914	57,351
Other expenses, net	-2,196	-6,368	29,489	7,497	17,646	13,294	10,613	27,862	28,422	69,415	30,471
Income (loss) from continuing operations before income taxes	25,272	56,286	-19,256	36,269	30,656	6,550	16,765	-5,472	98,571	48,499	26,880
Income tax expense (benefit)	12,569	24,090	-6,672	16,526	24,051	3,413	9,288	-54,006	46,513	-17,254	-2,078
Income (loss) from continuing operations	12,703	32,196	-12,584	19,743	6,605	3,137	7,477	48,534	52,058	65,753	28,958
Income (loss) from discontinued operations, net of income taxes	4	0	0	-5	-6	-2	35	32	-1	59	2,939
Net income (loss)	12,707	32,196	-12,584	19,738	6,599	3,135	7,512	48,566	52,057	65,812	31,897
Less: net income attributable to noncontrolling interests	4,633	6,934	5,025	6,150	3,319	5,054	3,943	5,143	22,817	17,710	9,797
Net income (loss) attributable to SemGroup	$8,074	$25,262	($17,609)	$13,588	$3,280	($1,919)	$3,569	$43,423	$29,240	$48,102	$22,100
Basic earnings (loss) per share, net	$0.19	$0.59	($0.41)	$0.32	$0.08	($0.05)	$0.08	$1.03	$0.69	$1.14	$0.53
Earnings Per Share, Diluted	$0.18	$0.59	($0.41)	$0.29	$0.08	($0.05)	$0.08	$1.03	$0.68	$1.13	$0.52

Related_Party_Transactions_Det

Related Party Transactions (Details) (NGL Energy [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
NGL Energy [Member]
Related Party Transaction
Revenues from related party	$456,987	$796,440	$421,311
Purchases from related party	437,015	669,450	336,612
Reimbursements from NGL Energy for transition services	$168	$198	$575

Related_Party_Transactions_Det1

Related Party Transactions (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Glass Mountain Pipeline LLC [Member]
Related Party Transactions (Textual) [Abstract]
Related Party Transaction, Expenses from Transactions with Related Party	$800,000
Related Party Reimbursement of Expense from a Related Party Transaction	700,000
White Cliffs Pipeline, LLC [Member]
Related Party Transactions (Textual) [Abstract]
Revenues from related party	2,900,000	2,900,000	2,500,000
Related Party Transaction, Expenses from Transactions with Related Party	0
Law Firm [Member]
Related Party Transactions (Textual) [Abstract]
Legal fees	1,300,000	1,900,000	1,700,000
White Cliffs Pipeline, LLC [Member] | Law Firm [Member]
Related Party Transactions (Textual) [Abstract]
Legal fees	$100,000	$200,000	$100,000

Condensed_Consolidating_Guaran2

Condensed Consolidating Guarantor Financial Statements (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash and cash equivalents	$40,598,000				$79,351,000				$40,598,000	$79,351,000	$80,029,000	$73,613,000
Restricted cash	6,980,000				5,119,000				6,980,000	5,119,000
Accounts Receivable, net	351,334,000				323,965,000				351,334,000	323,965,000
Receivable from affiliates	16,819,000				67,273,000				16,819,000	67,273,000
Inventories	43,532,000				44,295,000				43,532,000	44,295,000
Other current assets	20,017,000				14,011,000				20,017,000	14,011,000
Total current assets	479,280,000				534,014,000				479,280,000	534,014,000
Property, plant and equipment	1,256,825,000				1,105,728,000				1,256,825,000	1,105,728,000
Equity method investments	577,920,000				565,124,000				577,920,000	565,124,000
Goodwill	58,326,000				62,021,000				58,326,000	62,021,000	9,884,000	9,453,000
Other intangible assets	173,065,000				174,838,000				173,065,000	174,838,000
Other noncurrent assets	44,386,000				28,889,000				44,386,000	28,889,000
Total assets	2,589,802,000				2,470,614,000				2,589,802,000	2,470,614,000
Accounts payable	257,177,000				254,467,000				257,177,000	254,467,000
Due to Related Parties, Current	13,460,000				62,279,000				13,460,000	62,279,000
Accrued liabilities	92,694,000				83,429,000				92,694,000	83,429,000
Payables to pre-petition creditors	3,129,000				3,177,000				3,129,000	3,177,000
Deferred revenue	23,688,000				25,538,000				23,688,000	25,538,000
Other Liabilities, Current	1,474,000				12,153,000				1,474,000	12,153,000
Other Liabilities, Current					70,287,000					70,287,000
Current portion of long-term debt	40,000				37,000				40,000	37,000
Total current liabilities	391,662,000				499,214,000				391,662,000	499,214,000
Long-term debt	767,092,000				615,088,000				767,092,000	615,088,000
Deferred income taxes	161,956,000				100,945,000				161,956,000	100,945,000
Other noncurrent liabilities	49,655,000				41,504,000				49,655,000	41,504,000
Commitments and contingencies
Stockholders' Equity Attributable to Parent	1,149,508,000				1,053,902,000				1,149,508,000	1,053,902,000
Noncontrolling interests in consolidated subsidiaries	69,929,000				159,961,000				69,929,000	159,961,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,219,437,000				1,213,863,000				1,219,437,000	1,213,863,000	1,021,528,000	978,665,000
Liabilities and Equity	2,589,802,000				2,470,614,000				2,589,802,000	2,470,614,000
Sales Revenue, Goods, Gross									1,780,314,000	1,145,104,000	953,738,000
Sales Revenue, Services, Other									233,239,000	140,198,000	117,721,000
Other Revenue, Net									109,026,000	141,714,000	166,038,000
Revenue	547,237,000	594,235,000	482,224,000	498,883,000	457,328,000	357,748,000	324,244,000	287,696,000	2,122,579,000	1,427,016,000	1,237,497,000
Costs of products sold									1,623,358,000	1,020,100,000	874,885,000
Operating Costs and Expenses									246,613,000	223,585,000	224,700,000
General and administrative									87,845,000	78,597,000	71,918,000
Depreciation and amortization									98,397,000	66,409,000	48,210,000
Loss (gain) on disposal or impairment of long-lived assets, net	11,959,000	1,376,000	19,315,000	-58,000	-109,000	408,000	-376,000	-162,000	32,592,000	-239,000	-3,531,000
Costs and Expenses	542,109,000	577,312,000	491,178,000	478,206,000	448,687,000	345,387,000	311,727,000	282,651,000	2,088,805,000	1,388,452,000	1,216,182,000
Earnings from equity method investments	15,827,000	14,223,000	19,187,000	14,962,000	12,788,000	7,483,000	14,861,000	17,345,000	64,199,000	52,477,000	36,036,000
Gain on issuance of common units by equity method investee	2,121,000	18,772,000	0	8,127,000	26,873,000	0	0	0	29,020,000	26,873,000	0
Operating income (loss)	23,076,000	49,918,000	10,233,000	43,766,000	48,302,000	19,844,000	27,378,000	22,390,000	126,993,000	117,914,000	57,351,000
Interest Expense									49,044,000	25,142,000	8,902,000
Foreign Currency Transaction Gain (Loss), before Tax									-86,000	-1,633,000	298,000
Other expense (income), net									-20,536,000	45,906,000	21,271,000
Other expenses, net	-2,196,000	-6,368,000	29,489,000	7,497,000	17,646,000	13,294,000	10,613,000	27,862,000	28,422,000	69,415,000	30,471,000
Income (loss) from continuing operations before income taxes	25,272,000	56,286,000	-19,256,000	36,269,000	30,656,000	6,550,000	16,765,000	-5,472,000	98,571,000	48,499,000	26,880,000
Income tax expense (benefit)	12,569,000	24,090,000	-6,672,000	16,526,000	24,051,000	3,413,000	9,288,000	-54,006,000	46,513,000	-17,254,000	-2,078,000
Income (Loss) from Continuing Operations Attributable to Parent									52,058,000	65,753,000	28,958,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	4,000	0	0	-5,000	-6,000	-2,000	35,000	32,000	-1,000	59,000	2,939,000
Net income (loss)	12,707,000	32,196,000	-12,584,000	19,738,000	6,599,000	3,135,000	7,512,000	48,566,000	52,057,000	65,812,000	31,897,000
Less: net income attributable to noncontrolling interests	4,633,000	6,934,000	5,025,000	6,150,000	3,319,000	5,054,000	3,943,000	5,143,000	22,817,000	17,710,000	9,797,000
Net income (loss) attributable to SemGroup	8,074,000	25,262,000	-17,609,000	13,588,000	3,280,000	-1,919,000	3,569,000	43,423,000	29,240,000	48,102,000	22,100,000
Other Comprehensive Income (Loss), Net of Tax									-24,287,000	-1,555,000	12,576,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									27,770,000	64,257,000	44,473,000
Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest									22,817,000	17,710,000	9,797,000
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									4,953,000	46,547,000	34,676,000
Net Cash Provided by (Used in) Operating Activities									181,658,000	173,409,000	79,642,000
Capital expenditures									-270,506,000	-215,609,000	-119,319,000
Proceeds from sale of long-lived assets									4,445,000	1,279,000	2,641,000
Investments in non-consolidated subsidiaries									-71,131,000	-173,868,000	-78,253,000
Payments to acquire businesses									-44,508,000	-362,456,000	0
Proceeds from sale of non-consolidated affiliate											3,500,000
Proceeds from the sale of SemStream assets									0	0	12,250,000
Proceeds from Sale of Equity Method Investments									79,741,000	0	0
Distributions from equity method investments in excess of equity in earnings									11,734,000	12,246,000	17,290,000
Net Cash Provided by (Used in) Investing Activities									-290,225,000	-738,408,000	-161,891,000
Payments of Debt Issuance Costs									-8,686,000	-14,936,000	-707,000
Proceeds from Issuance of Long-term Debt and Capital Securities, Net									1,254,244,000	1,268,474,000	318,000,000
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities									-1,102,272,000	-859,412,000	-222,066,000
Proceeds from issuance of Rose Rock Midstream, L.P. common units, net of offering costs									0	210,226,000	0
Distributions to noncontrolling interests									-28,494,000	-17,647,000	-8,502,000
Proceeds from warrant exercises									1,451,000	225,000	0
Repurchase of common stock									-719,000	-371,000	-242,000
Dividends paid									-44,206,000	-25,429,000	0
Intercompany payments and receipts									0	0	0
Net Cash Provided by (Used in) Financing Activities									73,308,000	561,130,000	86,483,000
Effect of exchange rate changes on cash and cash equivalents									-3,494,000	3,191,000	-610,000
Cash and Cash Equivalents, Period Increase (Decrease)									-38,753,000	-678,000	3,624,000
Change in cash and cash equivalents included in discontinued operations									0	0	2,792,000
Change in cash and cash equivalents from continuing operations									-38,753,000	-678,000	6,416,000
Proceeds from the sale of equity method investments 2									0
Proceeds from issuance of common stock under employee stock purchase plan									340,000	0	0
Excess tax benefit from equity-based awards									1,650,000	0	0
Parent Company [Member]
Cash and cash equivalents	9,254,000				2,545,000				9,254,000	2,545,000	19,123,000	111,000
Restricted cash	3,856,000				3,851,000				3,856,000	3,851,000
Accounts Receivable, net	9,669,000				649,000				9,669,000	649,000
Receivable from affiliates	2,512,000				1,519,000				2,512,000	1,519,000
Inventories	0				0				0	0
Other current assets	10,498,000				8,712,000				10,498,000	8,712,000
Total current assets	35,789,000				17,276,000				35,789,000	17,276,000
Property, plant and equipment	4,112,000				4,114,000				4,112,000	4,114,000
Equity method investments	1,551,825,000				1,511,922,000				1,551,825,000	1,511,922,000
Goodwill	0				0				0	0
Other intangible assets	26,000				31,000				26,000	31,000
Other noncurrent assets	24,555,000				15,263,000				24,555,000	15,263,000
Total assets	1,616,307,000				1,548,606,000				1,616,307,000	1,548,606,000
Accounts payable	649,000				1,172,000				649,000	1,172,000
Due to Related Parties, Current	21,000				17,000				21,000	17,000
Accrued liabilities	11,989,000				10,072,000				11,989,000	10,072,000
Payables to pre-petition creditors	3,129,000				3,124,000				3,129,000	3,124,000
Deferred revenue	0				0				0	0
Other Liabilities, Current	224,000								224,000
Other Liabilities, Current					61,875,000					61,875,000
Current portion of long-term debt	0				0				0	0
Total current liabilities	16,012,000				76,260,000				16,012,000	76,260,000
Long-term debt	335,000,000				370,000,000				335,000,000	370,000,000
Deferred income taxes	112,897,000				48,436,000				112,897,000	48,436,000
Other noncurrent liabilities	2,886,000				8,000				2,886,000	8,000
Stockholders' Equity Attributable to Parent	1,149,512,000				1,053,902,000				1,149,512,000	1,053,902,000
Noncontrolling interests in consolidated subsidiaries	0				0				0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,149,512,000				1,053,902,000				1,149,512,000	1,053,902,000
Liabilities and Equity	1,616,307,000				1,548,606,000				1,616,307,000	1,548,606,000
Sales Revenue, Goods, Gross									0	0	0
Sales Revenue, Services, Other									0	0	0
Other Revenue, Net									0	0	0
Revenue									0	0	0
Costs of products sold									0	0	0
Operating Costs and Expenses									0	0	0
General and administrative									22,394,000	21,560,000	22,105,000
Depreciation and amortization									1,678,000	2,001,000	2,496,000
Loss (gain) on disposal or impairment of long-lived assets, net									5,945,000	0	0
Costs and Expenses									30,017,000	23,561,000	24,601,000
Earnings from equity method investments									48,760,000	67,965,000	66,671,000
Gain on issuance of common units by equity method investee									29,020,000	26,873,000
Operating income (loss)									47,763,000	71,277,000	42,070,000
Interest Expense									8,423,000	4,826,000	3,942,000
Foreign Currency Transaction Gain (Loss), before Tax									0	0	0
Other expense (income), net									-24,092,000	40,928,000	15,698,000
Other expenses, net									-15,669,000	45,754,000	19,640,000
Income (loss) from continuing operations before income taxes									63,432,000	25,523,000	22,430,000
Income tax expense (benefit)									34,192,000	-22,579,000	334,000
Income (Loss) from Continuing Operations Attributable to Parent									29,240,000	48,102,000	22,096,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									0	0	4,000
Net income (loss)									29,240,000	48,102,000	22,100,000
Net income (loss) attributable to SemGroup									29,240,000	48,102,000	22,100,000
Other Comprehensive Income (Loss), Net of Tax									5,159,000	-1,517,000	917,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									34,399,000	46,585,000	23,017,000
Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest									0	0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									34,399,000	46,585,000	23,017,000
Net Cash Provided by (Used in) Operating Activities									27,393,000	20,130,000	-4,535,000
Capital expenditures									-1,672,000	-734,000	-1,977,000
Proceeds from sale of long-lived assets									0	23,000	19,000
Investments in non-consolidated subsidiaries									0	-18,775,000	-1,740,000
Payments to acquire businesses									0	0
Proceeds from sale of non-consolidated affiliate											0
Proceeds from the sale of SemStream assets											12,250,000
Proceeds from Sale of Equity Method Investments									79,741,000	362,600,000
Distributions from equity method investments in excess of equity in earnings									1,843,000	0	9,218,000
Net Cash Provided by (Used in) Investing Activities									194,324,000	343,114,000	17,770,000
Payments of Debt Issuance Costs									-93,000	-10,866,000	-455,000
Proceeds from Issuance of Long-term Debt and Capital Securities, Net									405,500,000	706,000,000	318,000,000
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities									-440,500,000	-537,500,000	-194,000,000
Proceeds from issuance of Rose Rock Midstream, L.P. common units, net of offering costs										0
Distributions to noncontrolling interests									0	0	0
Proceeds from warrant exercises									1,451,000	225,000
Repurchase of common stock									-719,000	-371,000	-242,000
Dividends paid									-44,206,000	-25,429,000
Intercompany payments and receipts									-138,431,000	-511,881,000	-117,526,000
Net Cash Provided by (Used in) Financing Activities									-215,008,000	-379,822,000	5,777,000
Effect of exchange rate changes on cash and cash equivalents									0	0	0
Cash and Cash Equivalents, Period Increase (Decrease)									6,709,000	-16,578,000	19,012,000
Change in cash and cash equivalents included in discontinued operations											0
Change in cash and cash equivalents from continuing operations											19,012,000
Proceeds from the sale of equity method investments 2									114,412,000
Proceeds from issuance of common stock under employee stock purchase plan									340,000
Excess tax benefit from equity-based awards									1,650,000
Guarantor Subsidiaries [Member]
Cash and cash equivalents	0				0				0	0	0	0
Restricted cash	0				0				0	0
Accounts Receivable, net	32,932,000				14,642,000				32,932,000	14,642,000
Receivable from affiliates	6,628,000				14,063,000				6,628,000	14,063,000
Inventories	248,000				1,046,000				248,000	1,046,000
Other current assets	615,000				193,000				615,000	193,000
Total current assets	40,423,000				29,944,000				40,423,000	29,944,000
Property, plant and equipment	512,508,000				366,067,000				512,508,000	366,067,000
Equity method investments	692,872,000				461,056,000				692,872,000	461,056,000
Goodwill	13,052,000				23,839,000				13,052,000	23,839,000
Other intangible assets	152,383,000				163,144,000				152,383,000	163,144,000
Other noncurrent assets	958,000				1,302,000				958,000	1,302,000
Total assets	1,412,196,000				1,045,352,000				1,412,196,000	1,045,352,000
Accounts payable	22,477,000				24,234,000				22,477,000	24,234,000
Due to Related Parties, Current	52,000				115,000				52,000	115,000
Accrued liabilities	19,154,000				17,341,000				19,154,000	17,341,000
Payables to pre-petition creditors	0				0				0	0
Deferred revenue	0				0				0	0
Other Liabilities, Current	707,000								707,000
Other Liabilities, Current					715,000					715,000
Current portion of long-term debt	0				0				0	0
Total current liabilities	42,390,000				42,405,000				42,390,000	42,405,000
Long-term debt	0				0				0	0
Deferred income taxes	0				0				0	0
Other noncurrent liabilities	0				0				0	0
Stockholders' Equity Attributable to Parent	1,369,806,000				1,002,947,000				1,369,806,000	1,002,947,000
Noncontrolling interests in consolidated subsidiaries	0				0				0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,369,806,000				1,002,947,000				1,369,806,000	1,002,947,000
Liabilities and Equity	1,412,196,000				1,045,352,000				1,412,196,000	1,045,352,000
Sales Revenue, Goods, Gross									338,621,000	224,072,000	123,424,000
Sales Revenue, Services, Other									44,592,000	3,868,000	1,198,000
Other Revenue, Net									0	0	387,000
Revenue									383,213,000	227,940,000	125,009,000
Costs of products sold									273,309,000	166,735,000	98,224,000
Operating Costs and Expenses									33,591,000	19,541,000	12,719,000
General and administrative									10,796,000	9,437,000	8,360,000
Depreciation and amortization									29,677,000	14,452,000	6,448,000
Loss (gain) on disposal or impairment of long-lived assets, net									54,698,000	668,000	276,000
Costs and Expenses									402,071,000	210,833,000	126,027,000
Earnings from equity method investments									102,866,000	54,995,000	85,330,000
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									84,008,000	72,102,000	84,312,000
Interest Expense									19,186,000	9,781,000	-240,000
Foreign Currency Transaction Gain (Loss), before Tax									0	0	0
Other expense (income), net									500,000	0	-21,000
Other expenses, net									19,686,000	9,781,000	-261,000
Income (loss) from continuing operations before income taxes									64,322,000	62,321,000	84,573,000
Income tax expense (benefit)									0	0	0
Income (Loss) from Continuing Operations Attributable to Parent									64,322,000	62,321,000	84,573,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									0	65,000	-17,000
Net income (loss)									64,322,000	62,386,000	84,556,000
Net income (loss) attributable to SemGroup									64,322,000	62,386,000	84,556,000
Other Comprehensive Income (Loss), Net of Tax									0	0	0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									64,322,000	62,386,000	84,556,000
Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest									0	0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									64,322,000	62,386,000	84,556,000
Net Cash Provided by (Used in) Operating Activities									56,178,000	24,642,000	6,236,000
Capital expenditures									-180,361,000	-123,246,000	-59,317,000
Proceeds from sale of long-lived assets									2,368,000	19,000	-202,000
Investments in non-consolidated subsidiaries									-16,201,000	-57,850,000	-74,434,000
Payments to acquire businesses									-514,000	-313,487,000
Proceeds from sale of non-consolidated affiliate											0
Proceeds from the sale of SemStream assets											0
Proceeds from Sale of Equity Method Investments									0	0
Distributions from equity method investments in excess of equity in earnings									2,344,000	0	0
Net Cash Provided by (Used in) Investing Activities									-192,364,000	-494,564,000	-133,953,000
Payments of Debt Issuance Costs									0	0	0
Proceeds from Issuance of Long-term Debt and Capital Securities, Net									0	0	0
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities									0	0	0
Proceeds from issuance of Rose Rock Midstream, L.P. common units, net of offering costs										0
Distributions to noncontrolling interests									0	0	0
Proceeds from warrant exercises									0	0
Repurchase of common stock									0	0	0
Dividends paid									0	0
Intercompany payments and receipts									136,186,000	469,922,000	127,717,000
Net Cash Provided by (Used in) Financing Activities									136,186,000	469,922,000	127,717,000
Effect of exchange rate changes on cash and cash equivalents									0	0	0
Cash and Cash Equivalents, Period Increase (Decrease)									0	0	0
Change in cash and cash equivalents included in discontinued operations											0
Change in cash and cash equivalents from continuing operations											0
Proceeds from the sale of equity method investments 2									0
Proceeds from issuance of common stock under employee stock purchase plan									0
Excess tax benefit from equity-based awards									0
Non-Guarantor Subsidiaries [Member]
Cash and cash equivalents	35,486,000				78,364,000				35,486,000	78,364,000	63,844,000	76,264,000
Restricted cash	3,124,000				1,268,000				3,124,000	1,268,000
Accounts Receivable, net	308,733,000				308,674,000				308,733,000	308,674,000
Receivable from affiliates	15,655,000				56,040,000				15,655,000	56,040,000
Inventories	43,284,000				43,249,000				43,284,000	43,249,000
Other current assets	8,904,000				5,106,000				8,904,000	5,106,000
Total current assets	415,186,000				492,701,000				415,186,000	492,701,000
Property, plant and equipment	740,205,000				735,547,000				740,205,000	735,547,000
Equity method investments	269,634,000				159,321,000				269,634,000	159,321,000
Goodwill	45,274,000				38,182,000				45,274,000	38,182,000
Other intangible assets	20,656,000				11,663,000				20,656,000	11,663,000
Other noncurrent assets	18,873,000				12,324,000				18,873,000	12,324,000
Total assets	1,509,828,000				1,449,738,000				1,509,828,000	1,449,738,000
Accounts payable	234,051,000				229,061,000				234,051,000	229,061,000
Due to Related Parties, Current	21,363,000				67,062,000				21,363,000	67,062,000
Accrued liabilities	61,549,000				56,011,000				61,549,000	56,011,000
Payables to pre-petition creditors	0				53,000				0	53,000
Deferred revenue	23,688,000				25,538,000				23,688,000	25,538,000
Other Liabilities, Current	543,000								543,000
Other Liabilities, Current					7,697,000					7,697,000
Current portion of long-term debt	40,000				37,000				40,000	37,000
Total current liabilities	341,234,000				385,459,000				341,234,000	385,459,000
Long-term debt	490,946,000				245,088,000				490,946,000	245,088,000
Deferred income taxes	49,059,000				52,509,000				49,059,000	52,509,000
Other noncurrent liabilities	46,769,000				41,496,000				46,769,000	41,496,000
Stockholders' Equity Attributable to Parent	511,891,000				565,225,000				511,891,000	565,225,000
Noncontrolling interests in consolidated subsidiaries	69,929,000				159,961,000				69,929,000	159,961,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	581,820,000				725,186,000				581,820,000	725,186,000
Liabilities and Equity	1,509,828,000				1,449,738,000				1,509,828,000	1,449,738,000
Sales Revenue, Goods, Gross									1,479,543,000	944,984,000	840,892,000
Sales Revenue, Services, Other									188,647,000	136,330,000	116,523,000
Other Revenue, Net									109,026,000	141,714,000	165,651,000
Revenue									1,777,216,000	1,223,028,000	1,123,066,000
Costs of products sold									1,387,899,000	877,317,000	787,239,000
Operating Costs and Expenses									213,022,000	204,044,000	211,981,000
General and administrative									54,655,000	47,600,000	41,453,000
Depreciation and amortization									67,042,000	49,956,000	39,266,000
Loss (gain) on disposal or impairment of long-lived assets, net									-28,051,000	-907,000	-3,807,000
Costs and Expenses									1,694,567,000	1,178,010,000	1,076,132,000
Earnings from equity method investments									49,620,000	44,203,000	36,439,000
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									132,269,000	89,221,000	83,373,000
Interest Expense									24,740,000	15,947,000	11,056,000
Foreign Currency Transaction Gain (Loss), before Tax									-86,000	-1,633,000	298,000
Other expense (income), net									-246,000	-434,000	-262,000
Other expenses, net									24,408,000	13,880,000	11,092,000
Income (loss) from continuing operations before income taxes									107,861,000	75,341,000	72,281,000
Income tax expense (benefit)									12,321,000	5,325,000	-2,412,000
Income (Loss) from Continuing Operations Attributable to Parent									95,540,000	70,016,000	74,693,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									-1,000	-6,000	2,952,000
Net income (loss)									95,539,000	70,010,000	77,645,000
Less: net income attributable to noncontrolling interests									22,817,000	17,710,000	9,797,000
Net income (loss) attributable to SemGroup									72,722,000	52,300,000	67,848,000
Other Comprehensive Income (Loss), Net of Tax									-29,446,000	-38,000	11,659,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									66,093,000	69,972,000	89,304,000
Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest									22,817,000	17,710,000	9,797,000
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									43,276,000	52,262,000	79,507,000
Net Cash Provided by (Used in) Operating Activities									188,376,000	148,872,000	93,534,000
Capital expenditures									-88,473,000	-91,629,000	-58,025,000
Proceeds from sale of long-lived assets									2,077,000	1,237,000	2,824,000
Investments in non-consolidated subsidiaries									-54,930,000	-97,243,000	-2,079,000
Payments to acquire businesses									-43,994,000	-48,969,000
Proceeds from sale of non-consolidated affiliate											3,500,000
Proceeds from the sale of SemStream assets											0
Proceeds from Sale of Equity Method Investments									0	0
Distributions from equity method investments in excess of equity in earnings									9,390,000	12,246,000	8,072,000
Net Cash Provided by (Used in) Investing Activities									-175,930,000	-224,358,000	-45,708,000
Payments of Debt Issuance Costs									-8,593,000	-4,070,000	-252,000
Proceeds from Issuance of Long-term Debt and Capital Securities, Net									848,744,000	562,474,000	0
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities									-661,772,000	-321,912,000	-28,066,000
Proceeds from issuance of Rose Rock Midstream, L.P. common units, net of offering costs										210,226,000
Distributions to noncontrolling interests									-28,494,000	-17,647,000	-8,502,000
Proceeds from warrant exercises									0	0
Repurchase of common stock									0	0	0
Dividends paid									0	0
Intercompany payments and receipts									-201,715,000	-342,256,000	-25,608,000
Net Cash Provided by (Used in) Financing Activities									-51,830,000	86,815,000	-62,428,000
Effect of exchange rate changes on cash and cash equivalents									-3,494,000	3,191,000	-610,000
Cash and Cash Equivalents, Period Increase (Decrease)									-42,878,000	14,520,000	-15,212,000
Change in cash and cash equivalents included in discontinued operations											2,792,000
Change in cash and cash equivalents from continuing operations											-12,420,000
Proceeds from the sale of equity method investments 2									0
Proceeds from issuance of common stock under employee stock purchase plan									0
Excess tax benefit from equity-based awards									0
Consolidation, Eliminations [Member]
Cash and cash equivalents	-4,142,000				-1,558,000				-4,142,000	-1,558,000	-2,938,000	-2,762,000
Restricted cash	0				0				0	0
Accounts Receivable, net	0				0				0	0
Receivable from affiliates	-7,976,000				-4,349,000				-7,976,000	-4,349,000
Inventories	0				0				0	0
Other current assets	0				0				0	0
Total current assets	-12,118,000				-5,907,000				-12,118,000	-5,907,000
Property, plant and equipment	0				0				0	0
Equity method investments	-1,936,411,000				-1,567,175,000				-1,936,411,000	-1,567,175,000
Goodwill	0				0				0	0
Other intangible assets	0				0				0	0
Other noncurrent assets	0				0				0	0
Total assets	-1,948,529,000				-1,573,082,000				-1,948,529,000	-1,573,082,000
Accounts payable	0				0				0	0
Due to Related Parties, Current	-7,976,000				-4,915,000				-7,976,000	-4,915,000
Accrued liabilities	2,000				5,000				2,000	5,000
Payables to pre-petition creditors	0				0				0	0
Deferred revenue	0				0				0	0
Other Liabilities, Current	0								0
Other Liabilities, Current					0					0
Current portion of long-term debt	0				0				0	0
Total current liabilities	-7,974,000				-4,910,000				-7,974,000	-4,910,000
Long-term debt	-58,854,000				0				-58,854,000	0
Deferred income taxes	0				0				0	0
Other noncurrent liabilities	0				0				0	0
Stockholders' Equity Attributable to Parent	-1,881,701,000				-1,568,172,000				-1,881,701,000	-1,568,172,000
Noncontrolling interests in consolidated subsidiaries	0				0				0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	-1,881,701,000				-1,568,172,000				-1,881,701,000	-1,568,172,000
Liabilities and Equity	-1,948,529,000				-1,573,082,000				-1,948,529,000	-1,573,082,000
Sales Revenue, Goods, Gross									-37,850,000	-23,952,000	-10,578,000
Sales Revenue, Services, Other									0	0	0
Other Revenue, Net									0	0	0
Revenue									-37,850,000	-23,952,000	-10,578,000
Costs of products sold									-37,850,000	-23,952,000	-10,578,000
Operating Costs and Expenses									0	0	0
General and administrative									0	0	0
Depreciation and amortization									0	0	0
Loss (gain) on disposal or impairment of long-lived assets, net									0	0	0
Costs and Expenses									-37,850,000	-23,952,000	-10,578,000
Earnings from equity method investments									-137,047,000	-114,686,000	-152,404,000
Gain on issuance of common units by equity method investee									0	0
Operating income (loss)									-137,047,000	-114,686,000	-152,404,000
Interest Expense									-3,305,000	-5,412,000	-5,856,000
Foreign Currency Transaction Gain (Loss), before Tax									0	0	0
Other expense (income), net									3,302,000	5,412,000	5,856,000
Other expenses, net									-3,000	0	0
Income (loss) from continuing operations before income taxes									-137,044,000	-114,686,000	-152,404,000
Income tax expense (benefit)									0	0	0
Income (Loss) from Continuing Operations Attributable to Parent									-137,044,000	-114,686,000	-152,404,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									0	0	0
Net income (loss)									-137,044,000	-114,686,000	-152,404,000
Net income (loss) attributable to SemGroup									-137,044,000	-114,686,000	-152,404,000
Other Comprehensive Income (Loss), Net of Tax									0	0	0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									-137,044,000	-114,686,000	-152,404,000
Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest									0	0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									-137,044,000	-114,686,000	-152,404,000
Net Cash Provided by (Used in) Operating Activities									-90,289,000	-20,235,000	-15,593,000
Capital expenditures									0	0	0
Proceeds from sale of long-lived assets									0	0	0
Investments in non-consolidated subsidiaries									0	0	0
Payments to acquire businesses									0	0
Proceeds from sale of non-consolidated affiliate											0
Proceeds from the sale of SemStream assets											0
Proceeds from Sale of Equity Method Investments									0	-362,600,000
Distributions from equity method investments in excess of equity in earnings									-1,843,000	0	0
Net Cash Provided by (Used in) Investing Activities									-116,255,000	-362,600,000	0
Payments of Debt Issuance Costs									0	0	0
Proceeds from Issuance of Long-term Debt and Capital Securities, Net									0	0	0
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities									0	0	0
Proceeds from issuance of Rose Rock Midstream, L.P. common units, net of offering costs										0
Distributions to noncontrolling interests									0	0	0
Proceeds from warrant exercises									0	0
Repurchase of common stock									0	0	0
Dividends paid									0	0
Intercompany payments and receipts									203,960,000	384,215,000	15,417,000
Net Cash Provided by (Used in) Financing Activities									203,960,000	384,215,000	15,417,000
Effect of exchange rate changes on cash and cash equivalents									0	0	0
Cash and Cash Equivalents, Period Increase (Decrease)									-2,584,000	1,380,000	-176,000
Change in cash and cash equivalents included in discontinued operations											0
Change in cash and cash equivalents from continuing operations											-176,000
Proceeds from the sale of equity method investments 2									-114,412,000
Proceeds from issuance of common stock under employee stock purchase plan									0
Excess tax benefit from equity-based awards									$0

Condensed_Consolidating_Guaran3

Condensed Consolidating Guarantor Financial Statements (Details Textual) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jun. 14, 2013
In Thousands, unless otherwise specified
Senior notes	$300,000
Corporate Segment [Member]
Senior notes	$300,000	$300,000	$300,000
Senior Notes [Member]
Debt instrument, interest rate stated percentage	7.50%
Senior Notes [Member] | Corporate Segment [Member]
Debt instrument, interest rate stated percentage	7.50%