Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Financial Instruments - Summary of Changes in Fair Value of Company's Earn-Out Liability (Details)

v3.20.1
Fair Value of Financial Instruments - Summary of Changes in Fair Value of Company's Earn-Out Liability (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Earn-out payments during the period $ 863 $ 190
Level 3 Inputs    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance at December 31, 2019 9,154  
Earn-out payments during the period (1,155)  
Changes in fair value during the period 4  
Balance at March 31, 2020 8,003  
MUSA-Stainless | Level 3 Inputs    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance at December 31, 2019 2,403  
Earn-out payments during the period (476)  
Changes in fair value during the period 27  
Balance at March 31, 2020 1,954  
MUSA-Galvanized | Level 3 Inputs    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance at December 31, 2019 1,782  
Earn-out payments during the period (167)  
Changes in fair value during the period 70  
Balance at March 31, 2020 1,685  
American Stainless | Level 3 Inputs    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance at December 31, 2019 4,969  
Earn-out payments during the period (512)  
Changes in fair value during the period (93)  
Balance at March 31, 2020 $ 4,364