Loans Held for Investment - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Loans
Total loans	$ 7,345,250	$ 7,381,400
Allowance for loan losses	(106,739)	(61,136)	$ (58,809)	$ (59,486)
Loans held for investment, net	7,238,511	7,320,264
Commercial Real Estate
Loans
Total loans	3,062,042	3,000,523
Allowance for loan losses	(53,939)	(31,595)	(26,845)	(27,100)
Commercial \| Commercial And Industrial
Loans
Total loans	2,101,968	2,025,720
Allowance for loan losses	(38,550)	(17,964)	(21,268)	(21,980)
Construction and land development
Loans
Total loans	955,173	940,564
Allowance for loan losses	(6,360)	(4,878)	(5,908)	(6,061)
1 - 4 family residential
Loans
Total loans	676,630	791,020
Allowance for loan losses	(6,365)	(6,386)	(4,331)	(3,956)
Consumer
Loans
Total loans	43,187	47,046
Allowance for loan losses	(1,203)	(265)	(409)	(267)
Broker-dealer
Loans
Total loans	506,250	576,527
Allowance for loan losses	$ (322)	$ (48)	$ (48)	$ (122)

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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