Condensed Consolidating Financial Information (Balance Sheet) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 5,207	$ 5,400	$ 3,474	$ 0
Accounts and notes receivable	7,255	9,632
Inventories	3,397	3,354
Prepaid expenses and other current assets	837	851
Total Current Assets	16,696	19,237
Investments and long-term receivables	10,189	11,220
Net properties, plants and equipment	17,346	15,398
Goodwill	3,274	3,096	3,344
Intangibles	900	698
Other assets	336	149
Total Assets	48,741	49,798	48,073
Liabilities and Equity
Accounts payable	8,064	11,090
Short-term debt	842	24
Accrued income and other taxes	878	872
Employee benefit obligations	462	476
Other accruals	848	469
Total Current Liabilities	11,094	12,931
Long-term debt	7,842	6,131
Asset retirement obligations and accrued environmental costs	683	700
Deferred income taxes	5,491	6,125
Employee benefit obligations	1,305	921
Other liabilities and deferred credits	289	598
Total Liabilities	26,704	27,406
Common stock	12,812	16,291
Retained earnings	9,309	5,622
Accumulated other comprehensive income (loss)	(531)	37	(314)	122
Noncontrolling interests	447	442
Total Liabilities and Equity	48,741	49,798
Consolidating Adjustments [Member]
Assets
Accounts and notes receivable	(1,102)	(559)
Total Current Assets	(1,102)	(559)
Investments and long-term receivables	(43,479)	(55,945)
Other assets	(4)	(4)
Total Assets	(44,585)	(56,508)
Liabilities and Equity
Accounts payable	(1,102)	(559)
Total Current Liabilities	(1,102)	(559)
Deferred income taxes	(4)	(4)
Other liabilities and deferred credits	(4,041)	(13,690)
Total Liabilities	(5,147)	(14,253)
Common stock	(33,645)	(34,244)
Retained earnings	(6,317)	(7,655)
Accumulated other comprehensive income (loss)	524	(356)
Total Liabilities and Equity	(44,585)	(56,508)
Phillips 66 [Member]
Assets
Accounts and notes receivable	14	9
Prepaid expenses and other current assets	9	10
Total Current Assets	23	19
Investments and long-term receivables	30,141	33,178
Other assets	60	40
Total Assets	30,224	33,237
Liabilities and Equity
Accounts payable		1
Short-term debt	798
Other accruals	65	49
Total Current Liabilities	863	50
Long-term debt	7,457	5,796
Other liabilities and deferred credits	285	5,441
Total Liabilities	8,605	11,287
Common stock	12,812	16,291
Retained earnings	9,338	5,622
Accumulated other comprehensive income (loss)	(531)	37
Total Liabilities and Equity	30,224	33,237
Phillips 66 Company [Member]
Assets
Cash and cash equivalents	2,045	2,162	2,410
Accounts and notes receivable	5,069	2,169
Inventories	2,026	1,962
Prepaid expenses and other current assets	429	368
Total Current Assets	9,569	6,661
Investments and long-term receivables	18,896	27,416
Net properties, plants and equipment	12,267	12,031
Goodwill	3,040	3,094
Intangibles	694	694
Other assets	159	112
Total Assets	44,625	50,008
Liabilities and Equity
Accounts payable	5,618	7,502
Short-term debt	26	18
Accrued income and other taxes	356	250
Employee benefit obligations	409	422
Other accruals	242	179
Total Current Liabilities	6,651	8,371
Long-term debt	159	152
Asset retirement obligations and accrued environmental costs	494	527
Deferred income taxes	4,240	5,045
Employee benefit obligations	1,074	724
Other liabilities and deferred credits	1,919	2,153
Total Liabilities	14,537	16,972
Common stock	25,405	25,942
Retained earnings	5,214	7,057
Accumulated other comprehensive income (loss)	(531)	37
Total Liabilities and Equity	44,625	50,008
All Other Subsidiaries [Member]
Assets
Cash and cash equivalents	3,162	3,238	1,064
Accounts and notes receivable	3,274	8,013
Inventories	1,371	1,392
Prepaid expenses and other current assets	399	473
Total Current Assets	8,206	13,116
Investments and long-term receivables	4,631	6,571
Net properties, plants and equipment	5,079	3,367
Goodwill	234	2
Intangibles	206	4
Other assets	121	1
Total Assets	18,477	23,061
Liabilities and Equity
Accounts payable	3,548	4,146
Short-term debt	18	6
Accrued income and other taxes	522	622
Employee benefit obligations	53	54
Other accruals	541	241
Total Current Liabilities	4,682	5,069
Long-term debt	226	183
Asset retirement obligations and accrued environmental costs	189	173
Deferred income taxes	1,255	1,084
Employee benefit obligations	231	197
Other liabilities and deferred credits	2,126	6,694
Total Liabilities	8,709	13,400
Common stock	8,240	8,302
Retained earnings	1,074	598
Accumulated other comprehensive income (loss)	7	319
Noncontrolling interests	447	442
Total Liabilities and Equity	$ 18,477	$ 23,061