DERIVATIVE INSTRUMENTS AND OFFSETTING ASSETS AND LIABILITIES (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Forward Commitments [Member]
Derivative [Line Items]
Notional amount	$ 239,000	$ 314,700	$ 239,000	$ 314,700
Difference in carrying value and fair value, reflecting a loss		3,600
Difference in carrying value and fair value, reflecting a gain	673
Fixed Rate Mortgage Loans [Member]
Derivative [Line Items]
Notional amount	153,600	253,000	153,600	253,000
Difference in carrying value and fair value, reflecting a gain		8,800	4,000
Loan/Lease Interest Rate Swaps [Member]
Derivative [Line Items]
Notional amount	$ 336,300	$ 326,900	$ 336,300	$ 326,900
Average maturity			27 months	37 months
Average interest receive rate	3.40%	2.70%	3.40%	2.70%
Average interest pay rate	5.70%	5.60%	5.70%	5.60%