Summary Of Significant Accounting Policies Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Inventory Disclosure [Abstract]

Schedule of inventory by costing method [Table Text Block]

	December 31, 2015			December 31, 2014
	(In millions)
LIFO inventories
FIFO value	$	1,077		$	1,199
LIFO valuation reserve	(56		)	(53		)
LIFO inventories carrying value	1,021			1,146
FIFO inventories	2,756			3,058
Market inventories	4,066			4,699
Supplies and other inventories	400			471
Total inventories	$	8,243		$	9,374