Supplemental Cash Flow Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities:
Interest paid (net of amounts capitalized)	$ 307	$ 225	$ 268
Income taxes paid to taxing authorities	3,904	4,974	2,893
Commercial paper:
Issuances	10,870	13,880	421
Repayments	(10,935)	(13,680)	(421)
Net commercial paper	(65)	200	0
Noncash investing and financing activities:
Asset retirement costs capitalized, excluding acquisitions	319	257	148
Change in capital expenditure accrual	(9)	187	104
Liabilities Assumed	0	109	126
Asset Retirement Obligation, Liabilities Transferred	92	8	5
Debt payments made by United States Steel	$ 0	$ 20	$ 214