COMMITMENTS AND CONTINGENCIES COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 10,181,711	$ 9,201,665
Unused Commitments to Extend Credit	2,866,550
Commercial
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,322,374	2,465,877
Unused Commitments to Extend Credit	1,262,292
Lease financing
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	80,087	88,364
Unused Commitments to Extend Credit	0
Construction real estate
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	506,085	493,182
Unused Commitments to Extend Credit	433,673
Commercial real estate - investor
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	4,343,702	4,194,651
Unused Commitments to Extend Credit	135,504
Commercial real estate - investor
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,250,619
Commercial real estate-owner
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,093,083
Unused Commitments to Extend Credit	45,973
Residential real estate
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,043,745	1,055,949
Unused Commitments to Extend Credit	32,773
Home equity
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	764,171	771,869
Unused Commitments to Extend Credit	743,390
Installment
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	79,150	82,589
Unused Commitments to Extend Credit	19,216
Credit card
Other Commitments [Line Items]
Loans and Leases Receivable, Net of Deferred Income	42,397	$ 49,184
Unused Commitments to Extend Credit	$ 193,729