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)

v3.20.2
Fair Value of Financial Instruments - Summary of Changes in Fair Value of Company's Earn-Out Liability (Details) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Earn-out payments during the period $ 1,987 $ 1,346
Level 3 Inputs    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 9,154  
Earn-out payments during the period (2,279)  
Changes in fair value during the period (823)  
Ending balance 6,052  
MUSA-Stainless | Level 3 Inputs    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 2,403  
Earn-out payments during the period (919)  
Changes in fair value during the period (271)  
Ending balance 1,213  
MUSA-Galvanized | Level 3 Inputs    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 1,782  
Earn-out payments during the period (352)  
Changes in fair value during the period 74  
Ending balance 1,504  
American Stainless | Level 3 Inputs    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 4,969  
Earn-out payments during the period (1,008)  
Changes in fair value during the period (626)  
Ending balance $ 3,335