Condensed Consolidating Financial Information, Balance Sheet (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Current Assets
Cash and cash equivalents	$ 459	$ 1,000	$ 798	$ 1,238
Receivables, net of allowance for doubtful accounts	1,367	1,435
Short-term receivables from affiliates	0	0
Inventories	2,532	2,439
Prepayments and other current assets	223	200
Total Current Assets	4,581	5,074
Net Property, Plant and Equipment	9,180	9,045
Investment in Subsidiaries	0	0
Long-Term Receivables from Affiliates	0	0
Long-Term Intercompany Note Receivable	0	0
OTHER NONCURRENT ASSETS
Acquired intangibles, net	1,211	1,222
Other, net	1,311	1,150
Total Other Noncurrent Assets, Net	2,522	2,372
Total Assets	16,283	16,491
Current Liabilities:
Accounts payable	2,141	2,470
Short-term payables to affiliates	0	0
Other current liabilities	864	996
Total Current Liabilities	3,005	3,466
Long-Term Payables to Affiliates	0	0
Deferred Income Taxes	1,121	1,098
Other Noncurrent Liabilities	941	790
Debt, net of unamortized issuance costs	4,138	4,161
Long-Term Intercompany Note Payable	0	0
Equity-Tesoro Corporation	4,541	4,454
Equity-Noncontrolling Interest	2,537	2,522
Total Liabilities and Equity	16,283	16,491
Parent
Current Assets
Cash and cash equivalents	0	0	0	0
Receivables, net of allowance for doubtful accounts	9	6
Short-term receivables from affiliates	0	0
Inventories	0	0
Prepayments and other current assets	51	71
Total Current Assets	60	77
Net Property, Plant and Equipment	0	0
Investment in Subsidiaries	6,742	6,592
Long-Term Receivables from Affiliates	2,450	2,427
Long-Term Intercompany Note Receivable	0	0
OTHER NONCURRENT ASSETS
Acquired intangibles, net	0	0
Other, net	6	6
Total Other Noncurrent Assets, Net	6	6
Total Assets	9,258	9,102
Current Liabilities:
Accounts payable	0	1
Short-term payables to affiliates	0	0
Other current liabilities	193	148
Total Current Liabilities	193	149
Long-Term Payables to Affiliates	0	0
Deferred Income Taxes	1,121	1,098
Other Noncurrent Liabilities	446	447
Debt, net of unamortized issuance costs	1,581	1,578
Long-Term Intercompany Note Payable	1,376	1,376
Equity-Tesoro Corporation	4,541	4,454
Equity-Noncontrolling Interest	0	0
Total Liabilities and Equity	9,258	9,102
Guarantor Subsidiaries
Current Assets
Cash and cash equivalents	400	943	726	1,161
Receivables, net of allowance for doubtful accounts	884	912
Short-term receivables from affiliates	35	84
Inventories	2,398	2,088
Prepayments and other current assets	158	115
Total Current Assets	3,875	4,142
Net Property, Plant and Equipment	5,775	5,666
Investment in Subsidiaries	351	362
Long-Term Receivables from Affiliates	0	0
Long-Term Intercompany Note Receivable	0	0
OTHER NONCURRENT ASSETS
Acquired intangibles, net	245	249
Other, net	1,048	893
Total Other Noncurrent Assets, Net	1,293	1,142
Total Assets	11,294	11,312
Current Liabilities:
Accounts payable	1,639	1,779
Short-term payables to affiliates	0	0
Other current liabilities	535	717
Total Current Liabilities	2,174	2,496
Long-Term Payables to Affiliates	2,412	2,399
Deferred Income Taxes	0	0
Other Noncurrent Liabilities	431	296
Debt, net of unamortized issuance costs	37	39
Long-Term Intercompany Note Payable	0	0
Equity-Tesoro Corporation	6,240	6,082
Equity-Noncontrolling Interest	0	0
Total Liabilities and Equity	11,294	11,312
Non- Guarantors
Current Assets
Cash and cash equivalents	59	57	72	77
Receivables, net of allowance for doubtful accounts	474	517
Short-term receivables from affiliates	0	0
Inventories	134	351
Prepayments and other current assets	15	16
Total Current Assets	682	941
Net Property, Plant and Equipment	3,405	3,379
Investment in Subsidiaries	0	0
Long-Term Receivables from Affiliates	0	0
Long-Term Intercompany Note Receivable	1,376	1,376
OTHER NONCURRENT ASSETS
Acquired intangibles, net	966	973
Other, net	257	251
Total Other Noncurrent Assets, Net	1,223	1,224
Total Assets	6,686	6,920
Current Liabilities:
Accounts payable	502	690
Short-term payables to affiliates	35	84
Other current liabilities	137	133
Total Current Liabilities	674	907
Long-Term Payables to Affiliates	38	28
Deferred Income Taxes	0	0
Other Noncurrent Liabilities	64	47
Debt, net of unamortized issuance costs	2,520	2,544
Long-Term Intercompany Note Payable	0	0
Equity-Tesoro Corporation	853	872
Equity-Noncontrolling Interest	2,537	2,522
Total Liabilities and Equity	6,686	6,920
Eliminations
Current Assets
Cash and cash equivalents	0	0	0	0
Receivables, net of allowance for doubtful accounts	0	0
Short-term receivables from affiliates	(35)	(84)
Inventories	0	0
Prepayments and other current assets	(1)	(2)
Total Current Assets	(36)	(86)
Net Property, Plant and Equipment	0	0
Investment in Subsidiaries	(7,093)	(6,954)
Long-Term Receivables from Affiliates	(2,450)	(2,427)
Long-Term Intercompany Note Receivable	(1,376)	(1,376)
OTHER NONCURRENT ASSETS
Acquired intangibles, net	0	0
Other, net	0	0
Total Other Noncurrent Assets, Net	0	0
Total Assets	(10,955)	(10,843)
Current Liabilities:
Accounts payable	0	0
Short-term payables to affiliates	(35)	(84)
Other current liabilities	(1)	(2)
Total Current Liabilities	(36)	(86)
Long-Term Payables to Affiliates	(2,450)	(2,427)
Deferred Income Taxes	0	0
Other Noncurrent Liabilities	0	0
Debt, net of unamortized issuance costs	0	0
Long-Term Intercompany Note Payable	(1,376)	(1,376)
Equity-Tesoro Corporation	(7,093)	(6,954)
Equity-Noncontrolling Interest	0	0
Total Liabilities and Equity	$ (10,955)	$ (10,843)