Annual report pursuant to Section 13 and 15(d)

Goodwill - Narrative (Detail)

v3.8.0.1
Goodwill - Narrative (Detail)
3 Months Ended 12 Months Ended
Dec. 31, 2017
USD ($)
Sep. 30, 2017
USD ($)
Jul. 01, 2017
USD ($)
Apr. 01, 2017
USD ($)
Dec. 31, 2016
USD ($)
Oct. 01, 2016
USD ($)
Jul. 02, 2016
USD ($)
Apr. 02, 2016
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Oct. 02, 2016
reporting_unit
Goodwill [Line Items]                        
Number of reporting units have goodwill and subject to goodwill impairment test | reporting_unit                       9
Impairment charge $ 16,237,000 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 16,237,000 $ 0 $ 0  
Armstrong Areospace, Inc.                        
Goodwill [Line Items]                        
Impairment charge                 $ 16,200,000