LEASES: Lease Cost (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Leases [Abstract]
Right-of-use assets included in other assets, net	$ 58,751	$ 11,731
Operating lease, right-of-use asset, statement of financial position [Extensible Enumeration]	Other assets, net	Other assets, net
Short-term lease liabilities included in other accrued expenses	$ 7,158	$ 9,608
Operating lease, liability, current, statement of financial position [Extensible Enumeration]	Other Accrued Liabilities, Current	Other Accrued Liabilities, Current
Long-term lease liabilities included in other liabilities	$ 52,997	$ 4,158
Operating lease, liability, noncurrent, statement of financial position [Extensible Enumeration]	Other liabilities	Other liabilities
Weighted average remaining lease term	6 years 8 months 12 days	1 year 9 months 18 days
Weighted average discount rate	3.60%	5.00%