Long-Term Debt and Lease Financing Obligation - Additional Information (Detail)		3 Months Ended	12 Months Ended
	Feb. 27, 2015 USD ($)	Mar. 31, 2016 USD ($) Property Lease	Dec. 31, 2014 Property	Dec. 31, 2015 USD ($)	Feb. 01, 2013 USD ($)
Debt Instrument [Line Items]
Debt instrument, covenant compliance		As of March 31, 2016, we were in compliance with the covenants under our ABL Credit Agreement, the Term Loan Agreement and the indentures governing the 4.625 Notes and the 4.875 Notes.
Lease financing obligation		$ 46,900,000		$ 44,000,000
Lease financing original obligation term		10 years
2016		$ 2,600,000
2017		2,500,000
2018		2,200,000
2019		600,000
ABL Revolver [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		600,000,000
Maximum cash dividends if conditions are met		150,000,000
Availability under the credit facility that, if exceeded, limits the cash dividend payments the entity is allowed to make		$ 75,000,000
Consecutive period of borrowing availability under the credit facility used to determine cash dividend payments allowed		30 days
Fixed charge coverage ratio that, if exceeded, limits the cash dividend payments the entity is allowed to make		100.00%
Availability under the credit facility that, if exceeded, allows the entity to make additional cash dividend payments		$ 100,000,000
Fixed charge coverage ratio, if exceeded, allows the entity to make additional cash dividend payments		110.00%
Availability under the credit facility		$ 367,800,000
"ABL Revolver" outstanding balance		0		$ 0
Outstanding letters of credit		$ 72,900,000
ABL Revolver [Member] | Minimum [Member]
Debt Instrument [Line Items]
Variable interest rate margin		2.11%
ABL Revolver [Member] | Maximum [Member]
Debt Instrument [Line Items]
Variable interest rate margin		4.00%
Letter of Credit [Member]
Debt Instrument [Line Items]
Collateralized letter of credit expiration date		Feb. 02, 2015
4.625 Notes [Member]
Debt Instrument [Line Items]
Principal amount		$ 688,000,000
Stated Interest Rate		4.625%		4.625%
Debt instrument, interest payment description		Interest is payable semi-annually in arrears on February 15 and August 15 of each year.
4.875 Notes [Member]
Debt Instrument [Line Items]
Principal amount					$ 450,000,000
Stated Interest Rate		4.875%		4.875%
Debt instrument, interest payment description		Interest is payable semi-annually in arrears on May 15 and November 15 of each year.
Term Loan Facility [Member] | Due 2022 [Member]
Debt Instrument [Line Items]
Stated Interest Rate		4.00%
Term Loan Facility [Member] | Due 2022 [Member] | Axiall Holdco [Member]
Debt Instrument [Line Items]
Principal amount	$ 250,000,000
Additional amount of term loans permitted under term loan facility subject to certain conditions	$ 250,000,000
Maximum consolidated secured debt ratio related to additional amount of term loans permitted under term loan facility	2.50
Term Loan Facility [Member] | Due 2022 [Member] | Axiall Holdco [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Variable interest rate margin	1.50%
Variable interest rate basis floor (as a percent)	2.00%
Term Loan Facility [Member] | Due 2022 [Member] | Axiall Holdco [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Variable interest rate margin	3.25%
Variable interest rate basis floor (as a percent)	0.75%
Sale Leaseback Transaction of Properties [Member]
Debt Instrument [Line Items]
Sale-leaseback transaction, Description		In connection with the sale of our window and door profiles business, on March 31, 2016, we assigned the lease associated with one of the four properties that were recorded as part of such sale-leaseback transaction on our unaudited condensed consolidated balance sheets and extended the lease term for one of the remaining properties until March 31, 2019. In 2014, we had previously assigned the lease associated with another of the four properties that were recorded as part of such sale-leaseback transaction. Consequently, we are no longer the primary obligor under the two assigned leases
Sale-leaseback transaction, Number of properties | Property		4	4
Sale-leaseback transaction, Number of properties lease term extended | Lease		1
Sale-leaseback transaction, Extended the lease term		Mar. 31, 2019
Amount derecognized from property plant and equipment, net		$ 25,600,000
Lease financing obligation decreased		37,500,000
Deferred gain of leased properties		$ 11,900,000
Window and Door Profiles Business [Member]
Debt Instrument [Line Items]
Amount reclassified under discontinued operation, Number of properties | Property		2
Window and Door Profiles Business [Member] | Sale Leaseback Transaction of Properties [Member]
Debt Instrument [Line Items]
Sale-leaseback transaction, Number of properties assigned | Property		1	1