Annual report pursuant to Section 13 and 15(d)

Income Taxes - Narrative (Details)

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Income Taxes - Narrative (Details) - USD ($)
12 Months Ended
Dec. 31, 2016
Mar. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Income Tax Disclosure [Abstract]          
Undistributed earnings of foreign subsidiaries $ 7,200,000        
Operating Loss Carryforwards [Line Items]          
Valuation allowance 28,200,000   $ 18,400,000    
Foreign tax credit carryforward on deferred tax assets 0   3,500,000    
Future annual required taxable income for state tax purposes 177,000,000        
Unrecognized tax benefits 5,000,000   81,900,000 $ 76,100,000 $ 70,100,000
Unrecognized tax benefits that would impact effective tax rate 1,700,000        
Unrecognized tax benefit that would impact effective tax rate, net of federal tax benefits 1,600,000        
Decrease resulting from prior period tax positions 78,200,000        
Armstrong World Industries          
Operating Loss Carryforwards [Line Items]          
Foreign tax credit carryforward on deferred tax assets     3,500,000    
State          
Operating Loss Carryforwards [Line Items]          
Valuation allowance 4,900,000        
Operating loss carryforward 152,000,000 $ 155,200,000 94,900,000    
Decrease in NOL since separation from AWI 3,200,000        
Increase in foreign valuation allowance 4,500,000        
Foreign          
Operating Loss Carryforwards [Line Items]          
Valuation allowance 23,300,000        
Operating loss carryforward 79,900,000   $ 74,200,000    
Increase in foreign valuation allowance $ 5,300,000