Separation and Merger Transaction (Details) (USD $)	3 Months Ended	12 Months Ended	36 Months Ended	48 Months Ended			1 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2012	Jan. 31, 2013	Jan. 28, 2013	Jul. 19, 2012 Commodity Chemicals Segment	Dec. 31, 2012 Commodity Chemicals Segment	Dec. 31, 2011 Commodity Chemicals Segment	Dec. 31, 2010 Commodity Chemicals Segment	Sep. 28, 2012 Commodity Chemicals Segment
Separation And Merger Transaction [Line Items]
Common stock available for distribution in exchange						35,249,104
Final exchange ratio						3.2562
Treasury Stock, Shares, Acquired	10,825,227
Percent Reduction in number of Common Shares Outstanding					7.00%
Reconciling amount between Segment Income and Disposal Group income before income taxes		$ 2,000,000	$ 6,000,000	$ 4,000,000
Disposal Group, Including Discontinued Operation, Revenue								1,700,000,000	1,741,000,000	1,441,000,000
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax								368,000,000	376,000,000	187,000,000
Proceeds from separation of business							900,000,000
Value of shares to be received in new company after separation of business											1,800,000,000
Transaction expenses related to separation and merger transaction								$ 21,000,000