RELATED PARTY TRANSACTIONS (Details) - USD ($)		6 Months Ended		9 Months Ended	12 Months Ended			18 Months Ended
	Oct. 01, 2017	Sep. 30, 2017	Mar. 31, 2017	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2017	Feb. 28, 2017
Loan purchasing:
Loans purchased from MCB, net					$ (5,653,000)	$ 28,442,000	$ 39,061,000
Management and record keeping services:
Total management and record keeping services					24,033,000	28,684,000	21,848,000
Other transactions:
Capital contribution from parent					0	0	(9,022,000)
Tax (refunds)/payments (from)/to MCFC					(1,936,000)	1,896,000	2,134,000
Dividends paid to MCFC					1,909,000	474,000	2,270,000
MCB
Loan purchasing:
Loans purchased from MCB, net					113,582,000	164,909,000	194,519,000
Other transactions:
Fees paid to CBD in connection with loans purchased					1,273,000	1,585,000	1,995,000
Other reimbursements to MCB					$ 0	0	1,650,000
Additional disclosures
Special services fee (percent)		11500.00%			11500.00%				12500.00%
Fees paid for each loan purchased		$ 27.00					26.00	$ 25.00
MCB | Subsequent Event
Additional disclosures
Special services fee (percent)	125.00%
MCB | Monthly servicing for outstanding principal
Management and record keeping services:
Total management and record keeping services					$ 20,250,000	$ 22,557,000	$ 15,746,000
Additional disclosures
Service expense expressed as a percentage of outstanding principal (percent)			0.617%	0.567%			0.496%
Monthly collection fee					34.00%	34.00%
MCB | Monthly servicing for outstanding principal | Subsequent Event
Additional disclosures
Service expense expressed as a percentage of outstanding principal (percent)	0.604%
Monthly collection fee	46.00%
MCB | Annual base fee
Management and record keeping services:
Total management and record keeping services					$ 500,000	$ 500,000
MCB | Monthly special services fee to CBD
Management and record keeping services:
Total management and record keeping services					3,126,000	4,767,000	$ 4,836,000
MCB | Monthly base fee to CBD
Management and record keeping services:
Total management and record keeping services					500,000	500,000	500,000
MCFC
Other transactions:
Capital contribution from parent					0	0	(9,022,000)
Tax (refunds)/payments (from)/to MCFC					(1,936,000)	1,896,000	2,134,000
Dividends paid to MCFC					1,909,000	474,000	2,270,000
Direct cost allocations paid to MCFC					1,125,000	1,374,000	1,054,000
MCFC | Monthly cost sharing to MCFC
Management and record keeping services:
Total management and record keeping services					$ 157,000	$ 860,000	$ 766,000