Leases
 12 Months Ended
Dec. 31, 2021
Leases [Abstract]  
Leases
LEASES
We determine whether an arrangement contains a lease at inception. We have operating leases for office space, apartments, vehicles, and machinery and equipment. Our operating leases have lease terms of less than one year to ten years.
We do not separate lease components from non-lease components (e.g., common area maintenance, property taxes, and insurance) but account for both components in a contract as a single lease component.
The components of lease expense are as follows:
Year Ended
(In thousands)December 31, 2021December 31, 2020
Operating lease expense$11,477 $6,952 
Variable lease expense783 736 
Short-term lease expense62,124 53,528 
Total lease expense$74,384 $61,216 
Supplemental balance sheet information related to our operating leases is as follows:
Year Ended
(In thousands)December 31, 2021December 31, 2020
Right-of-use assets$43,651 $18,718 
Current lease liabilities (recorded in other accrued liabilities)$11,983 $6,245 
Long-term operating lease liabilities34,536 13,970 
Total operating lease liabilities$46,519 $20,215 
Additional ROU assets from operating lease arrangements of $35.3 million were recognized as non-cash asset additions during the year ended December 31, 2021. The increase in ROU assets is due primarily to new leases executed to support the OMDAC-SWACA contract extension and to replace expiring office space leases.
The weighted average remaining lease term and discount rate for our operating leases at December 31, 2021 were 5.2 years and 3.7%, respectively.
Maturities of lease liabilities at December 31, 2021 were as follows:
(In thousands)Payments due
2022$13,198 
202312,762 
20248,228 
20254,166 
20263,479 
After 202610,163 
Total minimum lease payments$51,996 
Less: Imputed interest(5,477)
Total operating lease liabilities$46,519