MORTGAGE BANKING OPERATIONS - Gain on Sale (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Gain on mortgage loan origination and sale activities [Line Items]
Gain on loan origination and sale activities	$ 22,541,000	$ 38,095,000
Net gains on mortgage loan origination and sales activities, discontinued operations	0	35,500,000
Single family [Member]
Gain on mortgage loan origination and sale activities [Line Items]
Gain on loan origination and sale activities	17,831,000	35,435,000
Commercial loans [Member]
Gain on mortgage loan origination and sale activities [Line Items]
Gain on loan origination and sale activities	$ 4,710,000	$ 2,660,000