FAIR VALUE (Fair value measurement recurring) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets
Equity securities with a readily determinable fair value	$ 20,531
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	1,001	$ 1,008
Derivative instruments	0	0
Liabilities
Derivative liabilities	0	0
Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	7,024,242	7,529,366
Derivative instruments	11,657	23,891
Liabilities
Derivative liabilities	11,682	25,099
Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Derivative instruments	0	0
Liabilities
Derivative liabilities	0	0
U.S. treasuries
Assets
Securities available for sale	1,001	1,008
U.S. agencies
Assets
Securities available for sale	86,109	193,384
Obligations of states and political subdivisions
Assets
Securities available for sale	1,637,917	2,085,033
Commercial mortgage-backed securities - agency
Assets
Securities available for sale	118,555	123,912
Commercial mortgage-backed securities - non-agency
Assets
Securities available for sale	693,963	600,888
Asset-backed securities
Assets
Securities available for sale	317,420	409,653
Corporate bonds
Assets
Securities available for sale	7,648	3,040
Recurring Basis
Assets
Equity securities with a readily determinable fair value	20,531	20,788
Total assets at fair value	7,038,604	7,555,603
Liabilities
Total liabilities at fair value	11,717	25,194
Recurring Basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Equity securities with a readily determinable fair value	0	0
Total assets at fair value	1,001	1,008
Liabilities
Total liabilities at fair value	0	0
Recurring Basis | Significant Other Observable Inputs (Level 2)
Assets
Equity securities with a readily determinable fair value	20,531	20,788
Total assets at fair value	7,036,907	7,553,289
Liabilities
Total liabilities at fair value	11,717	25,194
Recurring Basis | Significant Unobservable Inputs (Level 3)
Assets
Equity securities with a readily determinable fair value	0	0
Total assets at fair value	696	1,306
Liabilities
Total liabilities at fair value	0	0
Recurring Basis | Derivative financial instruments
Assets
Derivative instruments	11,657	23,891
Liabilities
Derivative liabilities	11,682	25,099
Recurring Basis | Derivative financial instruments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Derivative instruments	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis | Derivative financial instruments | Significant Other Observable Inputs (Level 2)
Assets
Derivative instruments	11,657	23,891
Liabilities
Derivative liabilities	11,682	25,099
Recurring Basis | Derivative financial instruments | Significant Unobservable Inputs (Level 3)
Assets
Derivative instruments	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis | Interest rate lock commitments
Assets
Derivative instruments	696	1,306
Recurring Basis | Interest rate lock commitments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Derivative instruments	0	0
Recurring Basis | Interest rate lock commitments | Significant Other Observable Inputs (Level 2)
Assets
Derivative instruments	0	0
Recurring Basis | Interest rate lock commitments | Significant Unobservable Inputs (Level 3)
Assets
Derivative instruments	696	1,306
Recurring Basis | Forward commitments
Assets
Derivative instruments	1,008	32
Liabilities
Derivative liabilities	35	95
Recurring Basis | Forward commitments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Derivative instruments	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis | Forward commitments | Significant Other Observable Inputs (Level 2)
Assets
Derivative instruments	1,008	32
Liabilities
Derivative liabilities	35	95
Recurring Basis | Forward commitments | Significant Unobservable Inputs (Level 3)
Assets
Derivative instruments	0	0
Liabilities
Derivative liabilities	0	0
Recurring Basis | U.S. treasuries
Assets
Securities available for sale	1,001	1,008
Recurring Basis | U.S. treasuries | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	1,001	1,008
Recurring Basis | U.S. treasuries | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	0	0
Recurring Basis | U.S. treasuries | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Recurring Basis | U.S. agencies
Assets
Securities available for sale	86,109	193,384
Recurring Basis | U.S. agencies | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Recurring Basis | U.S. agencies | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	86,109	193,384
Recurring Basis | U.S. agencies | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Recurring Basis | Obligations of states and political subdivisions
Assets
Securities available for sale	1,637,917	2,085,033
Recurring Basis | Obligations of states and political subdivisions | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Recurring Basis | Obligations of states and political subdivisions | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	1,637,917	2,085,033
Recurring Basis | Obligations of states and political subdivisions | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Recurring Basis | Mortgage-backed securities - agency
Assets
Securities available for sale	2,128,163	2,349,289
Recurring Basis | Mortgage-backed securities - agency | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Recurring Basis | Mortgage-backed securities - agency | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	2,128,163	2,349,289
Recurring Basis | Mortgage-backed securities - agency | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Recurring Basis | Mortgage-backed securities - non-agency
Assets
Securities available for sale	2,013,936	1,743,379
Recurring Basis | Mortgage-backed securities - non-agency | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Recurring Basis | Mortgage-backed securities - non-agency | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	2,013,936	1,743,379
Recurring Basis | Mortgage-backed securities - non-agency | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Recurring Basis | Commercial mortgage-backed securities - agency
Assets
Securities available for sale	118,555	123,912
Recurring Basis | Commercial mortgage-backed securities - agency | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Recurring Basis | Commercial mortgage-backed securities - agency | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	118,555	123,912
Recurring Basis | Commercial mortgage-backed securities - agency | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Recurring Basis | Commercial mortgage-backed securities - non-agency
Assets
Securities available for sale	693,963	600,888
Recurring Basis | Commercial mortgage-backed securities - non-agency | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Recurring Basis | Commercial mortgage-backed securities - non-agency | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	693,963	600,888
Recurring Basis | Commercial mortgage-backed securities - non-agency | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Recurring Basis | Asset-backed securities
Assets
Securities available for sale	317,420	409,653
Recurring Basis | Asset-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Recurring Basis | Asset-backed securities | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	317,420	409,653
Recurring Basis | Asset-backed securities | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	0	0
Recurring Basis | Corporate bonds
Assets
Securities available for sale	7,648	3,040
Recurring Basis | Corporate bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Securities available for sale	0	0
Recurring Basis | Corporate bonds | Significant Other Observable Inputs (Level 2)
Assets
Securities available for sale	7,648	3,040
Recurring Basis | Corporate bonds | Significant Unobservable Inputs (Level 3)
Assets
Securities available for sale	$ 0	$ 0