v3.19.3.a.u2
INCOME TAXES - Unrecognized tax benefits (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2019
USD ($)
item
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Reconciliation of the change in the amount of unrecognized tax benefits      
Balance at beginning of period $ 22,000 $ 15,300 $ 12,700
Gross increases-current period tax positions 10,500 7,300 3,200
Gross increases-prior periods tax position     300
Gross decreases-tax position in prior periods (1,500) (600)  
Impact of legislation change     (900)
Balance at end of period 31,000 22,000 15,300
Interest expense recognized   0 0
Unrecognized tax benefits that would impact the effective tax rate $ 12,200 15,200  
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      
Accrued interest and penalties   $ 100 $ 100