v3.20.4
INCOME TAXES - Unrecognized tax benefits (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2020
USD ($)
item
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Reconciliation of the change in the amount of unrecognized tax benefits      
Balance at beginning of period $ 31,000 $ 22,000 $ 15,300
Gross increases-current period tax positions 4,800 10,500 7,300
Gross decreases-tax position in prior periods (1,300) (1,500) (600)
Gross decreases-expiration of statute of limitations (1,000)    
Balance at end of period 33,500 31,000 22,000
Interest expense recognized 0 0 $ 0
Unrecognized tax benefits that would impact the effective tax rate 6,900 12,200  
Unrecognized tax positions $ 7,200    
Number of subsidiaries files income tax returns in the U.S. federal jurisdiction, and various state and foreign jurisdictions | item 1    
State      
Reconciliation of the change in the amount of unrecognized tax benefits      
Interest expense recognized $ 1,100 0  
Penalties 500    
Accrued interest and penalties $ 1,600 $ 100