PARENT COMPANY FINANCIAL INFORMATION - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets:
Cash and cash equivalents	$ 89,736	$ 71,356
Other	38,737	37,780
Total assets	3,941,863	3,003,986	$ 1,813,238
Liabilities and Stockholders' Equity:
Subordinated debentures	80,678	80,521
Advances from First Horizon Bank	5,354	0
Other	24,167	15,733
Liabilities and Equity, Total	3,941,863	3,003,986
Parent Company [Member]
Assets:
Cash and cash equivalents	5,941	3,081
Investment in subsidiary bank	616,807	434,352
Investments in statutory trusts	496	496
Bank owned life insurance	4,200	4,087
Other	2,292	2,927
Total assets	629,736	444,943
Liabilities and Stockholders' Equity:
Subordinated debentures	80,678	80,521
Advances from First Horizon Bank	5,354	0
Other	46	1,168
Stockholders' equity	543,658	363,254
Liabilities and Equity, Total	$ 629,736	$ 444,943