Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Principles of Consolidation - Statement of Operations (Details)

v3.10.0.1
Basis of Presentation and Principles of Consolidation - Statement of Operations (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Net sales $ 459.4 $ 374.8 $ 931.2 $ 794.3
Cost of sales (401.5) (330.6) (824.3) (699.5)
Gross profit 57.9 44.2 106.9 94.8
Selling, general and administrative expenses (23.1) (19.3) (46.5) (42.2)
Operating income 34.8 24.9 60.4 52.6
Interest expense (4.3) (4.8) (8.6) (9.5)
Other (expense) income, net (0.9) 4.5 (1.0) 4.2
Income before provision for income taxes 29.1 24.6 50.3 47.3
Provision for income taxes (8.0) (8.8) (13.3) (13.8)
Net income 21.1 15.8 37.0 33.5
Net income attributable to noncontrolling interest (0.1) (0.1) (0.2) (0.3)
Net income attributable to Global Brass and Copper Holdings, Inc. $ 21.0 $ 15.7 $ 36.8 $ 33.2
Net income attributable to Global Brass and Copper Holdings, Inc. per common share:        
Basic (in usd per share) $ 0.95 $ 0.72 $ 1.68 $ 1.54
Diluted (in usd per share) $ 0.94 $ 0.71 $ 1.66 $ 1.50
Weighted average common shares outstanding:        
Basic (in shares) 22.0 21.8 21.9 21.6
Diluted (in shares) 22.3 22.1 22.2 22.1
Previously Reported [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Net sales   $ 377.4   $ 770.7
Cost of sales   (332.7)   (676.1)
Gross profit   44.7   94.6
Selling, general and administrative expenses   (19.3)   (42.2)
Operating income   25.4   52.4
Interest expense   (4.8)   (9.5)
Other (expense) income, net   4.5   4.2
Income before provision for income taxes   25.1   47.1
Provision for income taxes   (8.9)   (13.7)
Net income   16.2   33.4
Net income attributable to noncontrolling interest   (0.1)   (0.3)
Net income attributable to Global Brass and Copper Holdings, Inc.   $ 16.1   $ 33.1
Net income attributable to Global Brass and Copper Holdings, Inc. per common share:        
Basic (in usd per share)   $ 0.74   $ 1.53
Diluted (in usd per share)   $ 0.73   $ 1.50
Weighted average common shares outstanding:        
Basic (in shares)   21.8   21.6
Diluted (in shares)   22.1   22.1
Restatement Adjustment [Member] | Accounting Standards Update 2014-09 [Member]        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Net sales   $ (2.6)   $ 23.6
Cost of sales   2.1   (23.4)
Gross profit   (0.5)   0.2
Operating income   (0.5)   0.2
Income before provision for income taxes   (0.5)   0.2
Provision for income taxes   0.1   (0.1)
Net income   (0.4)   0.1
Net income attributable to noncontrolling interest   0.0   0.0
Net income attributable to Global Brass and Copper Holdings, Inc.   $ (0.4)   $ 0.1
Net income attributable to Global Brass and Copper Holdings, Inc. per common share:        
Basic (in usd per share)   $ (0.02)   $ 0.01
Diluted (in usd per share)   $ (0.02)   $ 0.00
Weighted average common shares outstanding:        
Basic (in shares)   0.0   0.0
Diluted (in shares)   0.0   0.0