LEASES - Additional information (Details) - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
| LEASES |
|
|
|
| Lessee, Operating Lease, Existence of Option to Extend |
true
|
|
|
| Lessee, Operating Lease, Existence of Option to Terminate |
true
|
|
|
| Operating lease cost |
$ 34,300
|
|
|
| Variable lease cost |
400
|
|
|
| Short-term lease cost |
900
|
|
|
| Sublease income |
100
|
|
|
| Rent expense related to operating leases |
|
$ 11,700
|
$ 7,400
|
| Cash paid for amounts included in the measurement of operating lease liabilities |
12,700
|
10,800
|
|
| Right-of-use assets obtained in exchange for new or acquired operating lease liabilities |
39,800
|
57,900
|
|
| Reduction in right-of-use assets and lease liabilities |
28,300
|
2,900
|
|
| Operating Lease, Right-of-Use Asset, Amortization Expense |
$ 23,744
|
$ 11,940
|
|
| Weighted average lease term |
6 years 6 months
|
4 years 6 months
|
|
| Weighted average discount rate |
9.10%
|
7.20%
|
|
| San Francisco Office [Member] |
|
|
|
| LEASES |
|
|
|
| Reduction in right-of-use assets and lease liabilities |
$ 28,100
|
|
|
| Operating Lease, Right-of-Use Asset, Amortization Expense |
12,500
|
|
|
| Early termination fees |
$ 5,200
|
|
|
| Remaining lease term |
1 year
|
|
|
| Maximum |
|
|
|
| LEASES |
|
|
|
| Lease agreement term (in years) |
11 years
|
|
|