Non-Covered Loans and Allowance for Non-Covered Loan Losses - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Loans
Total loans	$ 5,783,853	$ 5,843,499
Allowance for loan losses	(55,157)	(54,186)
Non-covered loans, net	5,728,696	5,789,313
Noncovered
Loans
Total loans	5,783,853	5,843,499
Allowance for loan losses	(55,157)	(54,186)	$ (48,450)	$ (45,415)
Non-covered loans, net	5,728,696	5,789,313
Noncovered \| Commercial and industrial
Loans
Total loans	1,655,945	1,696,453
Allowance for loan losses	(21,679)	(21,369)	(20,169)	(19,845)
Noncovered \| Real estate
Loans
Total loans	2,852,245	2,816,767
Allowance for loan losses	(26,112)	(25,236)	(22,272)	(18,983)
Noncovered \| Construction and land development
Loans
Total loans	767,798	786,850
Allowance for loan losses	(6,879)	(7,002)	(5,561)	(6,064)
Noncovered \| Consumer
Loans
Total loans	42,656	41,352
Allowance for loan losses	(464)	(424)	(334)	(314)
Noncovered \| Broker-dealer
Loans
Total loans	465,209	502,077
Allowance for loan losses	$ (23)	$ (155)	$ (114)	$ (209)

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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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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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