ALLOWANCE FOR CREDIT LOSSES, Amortized Cost Basis (Details) - USD ($) $ in Thousands		6 Months Ended
		Sep. 30, 2020		Mar. 31, 2020
Credit Risk Profile, Segregated by Class [Abstract]
2021	[1]	$ 114,964
2020	[1]	35,682
2019	[1]	9,125
2018	[1]	2,643
2017	[1]	458
2016 and prior	[1]	70
Total	[1]	162,942
Transfers	[1],[2]	(60,445)
Net credit exposure	[1]	102,497
Unguaranteed residual value		12,644
Lease receivable and initial direct costs of notes receivable, net of amortization		364
Notes Receivable [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2021		70,867
2020		14,441
2019		3,595
2018		999
2017		38
2016 and prior		62
Total		90,002
Transfers	[2]	(39,518)
Net credit exposure		50,484
Unguaranteed residual value		0	[3]	$ 0	[4]
Lease receivable and initial direct costs of notes receivable, net of amortization	[5]	364		212
Lease Receivables [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2021		44,097
2020		21,241
2019		5,530
2018		1,644
2017		420
2016 and prior		8
Total		72,940
Transfers	[2]	(20,927)
Net credit exposure		52,013
Unguaranteed residual value		20,213	[3]	21,862	[4]
Lease receivable and initial direct costs of notes receivable, net of amortization	[5]	$ 0		$ 247
High CQR [Member] | Maximum [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loss rate on credit quality rating		1.00%
High CQR [Member] | Notes Receivable [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2021		$ 64,678
2020		9,744
2019		2,434
2018		947
2017		38
2016 and prior		0
Total		77,841
Transfers	[2]	(35,867)
Net credit exposure		41,974
High CQR [Member] | Lease Receivables [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2021		21,650
2020		11,826
2019		3,609
2018		998
2017		314
2016 and prior		8
Total		38,405
Transfers	[2]	(9,518)
Net credit exposure		$ 28,887
Average CQR [Member] | Minimum [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loss rate on credit quality rating		2.00%
Average CQR [Member] | Maximum [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loss rate on credit quality rating		10.00%
Average CQR [Member] | Notes Receivable [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2021		$ 6,189
2020		4,697
2019		837
2018		52
2017		0
2016 and prior		0
Total		11,775
Transfers	[2]	(3,651)
Net credit exposure		8,124
Average CQR [Member] | Lease Receivables [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2021		22,447
2020		9,415
2019		1,921
2018		646
2017		106
2016 and prior		0
Total		34,535
Transfers	[2]	(11,409)
Net credit exposure		$ 23,126
Low CQR [Member] | Minimum [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loss rate on credit quality rating		10.00%
Low CQR [Member] | Maximum [Member]
Credit Risk Profile, Segregated by Class [Abstract]
Loss rate on credit quality rating		100.00%
Low CQR [Member] | Notes Receivable [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2021		$ 0
2020		0
2019		324
2018		0
2017		0
2016 and prior		62
Total		386
Transfers	[2]	0
Net credit exposure		386
Low CQR [Member] | Lease Receivables [Member]
Credit Risk Profile, Segregated by Class [Abstract]
2021		0
2020		0
2019		0
2018		0
2017		0
2016 and prior		0
Total		0
Transfers	[2]	0
Net credit exposure		$ 0

[1] Unguaranteed residual values of $12,644 thousand that we retained after selling the related lease receivable and initial direct costs of notes receivable of $364 thousand are excluded from amortized cost.

[2] Transfers consist of receivables that have been transferred to third-party financial institutions on a non-recourse basis and receivables that are in the process of being transferred to third-party financial institutions.

[3] Includes unguaranteed residual values of $12,644 thousand that we retained after selling the related lease receivable.

[4] Includes unguaranteed residual values of $14,972 thousand for sales type leases, which have been sold and accounted for as sales.

[5] Refer to Note 7, “Allowance for Credit Losses” for details.