SUPPLEMENTAL GUARANTOR INFORMATION (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2013 Parent Company	Dec. 31, 2012 Parent Company	Mar. 31, 2012 Parent Company	Mar. 31, 2013 Eliminations	Dec. 31, 2012 Eliminations	Mar. 31, 2013 4.625 Notes, 4.875 Notes and Term Loan Guarantor Subsidiaries	Dec. 31, 2012 4.625 Notes, 4.875 Notes and Term Loan Guarantor Subsidiaries	Mar. 31, 2013 4.625 Notes, 4.875 Notes and Term Loan Non-Guarantor Subsidiaries	Dec. 31, 2012 4.625 Notes, 4.875 Notes and Term Loan Non-Guarantor Subsidiaries	Mar. 31, 2013 Splitco Notes	Mar. 31, 2013 4.875 Notes	Feb. 02, 2013 4.875 Notes	Mar. 31, 2013 9 percent notes	Dec. 31, 2012 9 percent notes	Dec. 31, 2012 9 percent notes Guarantor Subsidiaries	Mar. 31, 2012 9 percent notes Guarantor Subsidiaries	Dec. 31, 2011 9 percent notes Guarantor Subsidiaries	Dec. 31, 2012 9 percent notes Non-Guarantor Subsidiaries	Mar. 31, 2012 9 percent notes Non-Guarantor Subsidiaries	Dec. 31, 2011 9 percent notes Non-Guarantor Subsidiaries
Supplemental Condensed Consolidating Balance Sheet Information
Interest rate (as a percent)														4.625%	4.875%	4.875%	9.00%	9.00%
Assets
Cash and cash equivalents	$ 69.2	$ 200.3	$ 39.0	$ 88.6			$ 0			$ 8.6	$ 131.4	$ 60.6	$ 68.9						$ 131.0	$ 20.8	$ 43.4	$ 69.3	$ 18.2	$ 45.2
Receivables, net of allowance for doubtful accounts	636.9	314.9			1.5	2.2		(699.6)	(731.7)	1,243.9		91.1							989.1			55.3
Inventories	443.6	288.4								328.8		114.8							201.6			86.8
Prepaid expenses and other	30.8	14.7								26.5		4.3							11.9			2.8
Deferred income taxes	1.3	21.1			7.9	7.9		(6.8)				0.2							13.0			0.2
Total current assets	1,181.8	839.4			9.4	10.1		(706.4)	(731.7)	1,607.8		271.0							1,346.6			214.4
Property, plant and equipment, net	1,635.9	637.7			1.5	1.5				1,297.1		337.3							422.0			214.2
Long term receivables - affiliates					448.7	458.0		(535.1)	(467.4)	86.4									9.4
Goodwill	1,667.2	217.2								1,395.7		271.5							105.0			112.2
Intangibles, net	1,253.7	43.4								1,066.9		186.8							40.9			2.5
Other assets, net	86.8	63.6			12.9	14.0				61.2		12.7							38.8			10.8
Investments in Subsidiaries					3,310.0	1,446.5		(3,630.6)	(1,446.5)	320.6
Total assets	5,825.4	1,801.3			3,782.5	1,930.1		(4,872.1)	(2,645.6)	5,835.7		1,079.3							1,962.7			554.1
Liabilities and Equity
Current portion of long-term debt	55.1				52.3					2.8
Accounts payable	344.2	211.2			708.6	745.1		(699.6)	(731.7)	285.5		49.7							176.3			21.5
Interest payable	9.5	18.9			4.0	18.9				5.5
Income taxes payable	6.4	15.1								3.5		2.9							13.9			1.2
Accrued compensation	34.3	44.7								23.7		10.6							29.4			15.3
Current deferred tax liability	5.4							(6.8)		12.1		0.1
Other accrued current liabilities	111.5	61.2			1.2	1.0				79.6		30.7							38.5			21.7
Total current liabilities	566.4	351.1			766.1	765.0		(706.4)	(731.7)	412.7		94.0							258.1			59.7
Long-term debt	1,418.2	448.1			536.7	448.1				881.5
Long-term payables - affiliates								(535.1)	(467.4)			535.1										467.4
Lease financing obligation	110.0	112.3										110.0										112.3
Deferred income taxes	777.2	177.9			13.5	16.9				716.2		47.5							161.0
Pensions and other postretirement benefits	327.5	48.3								315.9		11.6							48.3
Other non-current liabilities	132.9	60.1			104.0	96.6		(103.9)	(104.8)	111.2		21.6							48.7			19.6
Total liabilities	3,332.2	1,197.8			1,420.3	1,326.6		(1,345.4)	(1,303.9)	2,437.5		819.8							516.1			659.0
Equity:
Total Axiall stockholders' equity (deficit)	2,362.2	603.5			2,362.2	603.5		(3,526.7)	(1,341.7)	3,398.2		128.5							1,446.6			(104.9)
Noncontrolling interest	131.0											131.0
Total equity	2,493.2	603.5			2,362.2	603.5		(3,526.7)	(1,341.7)	3,398.2		259.5							1,446.6			(104.9)
Total liabilities and equity	$ 5,825.4	$ 1,801.3			$ 3,782.5	$ 1,930.1		$ (4,872.1)	$ (2,645.6)	$ 5,835.7		$ 1,079.3							$ 1,962.7			$ 554.1