FINANCIAL INSTRUMENTS (Investments) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Financial Instruments [Abstact]
Investing Results, Proceeds from sales of available-for-sale securities	$ 764	$ 981	$ 593
Investing Results, Gross realized gains	44	69	32
Investing Results, Gross realized losses	(14)	(26)	(28)
Contractual Maturities of Debt Securities, Within one year, Amortized Cost	23
Contractual Maturities of Debt Securities, One to five years, Amortized Cost	476
Contractual Maturities of Debt Securities, Six to ten years, Amortized Cost	480
Contractual Maturities of Debt Securities, After ten years, Amortized Cost	229
Contractual Maturities of Debt Securities, Total, Amortized Cost	1,208
Contractual Maturities of Debt Securities, Within one year, Fair Value	24
Contractual Maturities of Debt Securities, One to five years, Fair Value	520
Contractual Maturities of Debt Securities, Six to ten years, Fair Value	524
Contractual Maturities of Debt Securities, After ten years, Fair Value	273
Contractual Maturities of Debt Securities, Total, Fair Value	1,341
Held-to-maturity securities	1,836	3,200
Investments in money market funds	1,090	35
Net unrealized gain recognized on trading securities	$ 26	$ 14

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Namespace Prefix:	dow_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

This item represents debt securities, at cost, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments, as defined), and fair value hedge accounting adjustments, if any, which are expected to mature after five years and through ten years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.