Income Taxes - Narrative (Details) - USD ($)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 30, 2015
Dec. 31, 2014
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]          
Increase (decrease) valuation allowance $ (200,000)        
Unrecognized tax benefits 0 $ 429,000 $ 0   $ 7,604,000
Settlements with tax authorities 429,000 0 0    
Tax settlements 0 0 7,604,000    
Interest expense related to tax matters 0 0 100,000    
Interest accrued for tax matters 0        
Income tax expense (benefit) excluding tax cuts and jobs act impact 12,200,000        
Interest payable 22,917,000 (13,532,000) (2,458,000)    
Tax Cuts and Jobs Act of 2017, transition tax for accumulated foreign earnings, income tax expense 400,000        
Tax Cuts and Jobs Act of 2017, change in tax rate, deferred tax asset, income tax expense (35,500,000)        
Tax Cuts and Jobs Act of 2017, acceleration of income, before taxes, recognized for tax purposes 76,900,000        
Selling, general and administrative expenses $ 60,728,000 $ 64,086,000 65,687,000    
Spinoff | Indemnified receivable          
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]          
Interest payable     3,200,000    
Income taxes     0 $ 3,200,000  
Indemnification receivable     0 3,300,000  
Selling, general and administrative expenses     3,300,000    
Spinoff | Indemnified receivable | Exelis          
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]          
Income tax indemnification amount     3,300,000    
Other non-current assets | Spinoff | Indemnified receivable          
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]          
Indemnification receivable       $ 100,000  
Tax Years Of Former Parent          
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]          
Tax settlements     6,900,000    
Tax Year 2014          
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]          
Tax settlements     $ 700,000