Loans and Allowance for Loan Losses - Summary of non acquired loans (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans and Allowance for Loan Losses
Loans, net	$ 11,313,113,000	$ 10,962,037,000
Deferred fees	751,000	697,000
Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	9,252,831,000	7,933,286,000	$ 6,492,155,000
Less allowance for non-acquired loan losses	(56,927,000)	(51,194,000)	(43,448,000)	$ (36,960,000)
Loans, net	9,195,904,000	7,882,092,000
Commercial non-owner occupied real estate \| Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	2,779,498,000	2,256,996,000
Commercial non-owner occupied real estate \| Construction and land development \| Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	968,360,000	841,445,000	830,875,000
Less allowance for non-acquired loan losses	(6,104,000)	(5,682,000)	(5,921,000)	(4,091,000)
Commercial non-owner occupied real estate \| Other commercial non-owner occupied real estate \| Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	1,811,138,000	1,415,551,000	1,008,893,000
Less allowance for non-acquired loan losses	(10,699,000)	(8,754,000)	(6,525,000)	(4,980,000)
Consumer loans \| Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	2,637,467,000	2,431,413,000
Consumer loans \| Home equity loans \| Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	518,628,000	495,148,000	437,642,000
Less allowance for non-acquired loan losses	(3,188,000)	(3,434,000)	(3,250,000)	(3,211,000)
Commercial and industrial \| Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	1,280,859,000	1,054,952,000	815,187,000
Less allowance for non-acquired loan losses	(8,339,000)	(7,454,000)	(5,488,000)	(4,842,000)
Other income producing property \| Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	218,617,000	214,353,000	193,847,000
Less allowance for non-acquired loan losses	(1,336,000)	(1,446,000)	(1,375,000)	(1,542,000)
Consumer \| Non-acquired loans
Loans and Allowance for Loan Losses
Total loans	538,481,000	448,664,000	378,985,000
Less allowance for non-acquired loan losses	$ (3,947,000)	$ (3,101,000)	$ (2,788,000)	$ (2,350,000)

The amount of deferred fees, net of deferred costs as of the reporting period.

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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 of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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