Loans and Allowance for Loan Losses - Allowance For Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Allowance for loan losses
Balance, beginning of period	$ 8,311	$ 6,250
Provision for loan losses	(1,406)	(240)
Loans charged to the allowance	(17)
Recoveries of loans previously charged off	5	60
Balance, end of period	9,705	6,550
Ending balance: individually evaluated for impairment	632		$ 362
Ending balance: collectively evaluated for impairment	9,073		7,949
Loans
Ending balance	1,573,190		1,374,660
Ending balance individually evaluated for impairment	9,305		7,336
Ending balance: collectively evaluated for impairment	1,563,885		1,367,324
Mortgage warehouse lines of credit
Allowance for loan losses
Balance, beginning of period	283	373
Provision for loan losses	(223)	192
Balance, end of period	506	181
Ending balance: individually evaluated for impairment	175
Ending balance: collectively evaluated for impairment	331		283
Loans
Ending balance	245,724		224,937
Ending balance individually evaluated for impairment	933
Ending balance: collectively evaluated for impairment	244,791		224,937
Residential real estate
Allowance for loan losses
Balance, beginning of period	1,587	2,170
Provision for loan losses	(76)	242
Recoveries of loans previously charged off	1
Balance, end of period	1,664	1,928
Ending balance: collectively evaluated for impairment	1,664		1,587
Loans
Ending balance	356,885		330,410
Ending balance individually evaluated for impairment	728		729
Ending balance: collectively evaluated for impairment	356,157		329,681
Multi-family and healthcare financing
Allowance for loan losses
Balance, beginning of period	3,502	1,962
Provision for loan losses	(748)	(135)
Balance, end of period	4,250	2,097
Ending balance: collectively evaluated for impairment	4,250		3,502
Loans
Ending balance	645,432		529,259
Ending balance individually evaluated for impairment	116
Ending balance: collectively evaluated for impairment	645,316		529,259
Commercial and commercial real estate
Allowance for loan losses
Balance, beginning of period	2,362	1,374
Provision for loan losses	(323)	(518)
Recoveries of loans previously charged off		26
Balance, end of period	2,685	1,918
Ending balance: individually evaluated for impairment	294		200
Ending balance: collectively evaluated for impairment	2,391		2,162
Loans
Ending balance	249,372		228,668
Ending balance individually evaluated for impairment	6,747		6,179
Ending balance: collectively evaluated for impairment	242,625		222,489
Agricultural production and real estate
Allowance for loan losses
Balance, beginning of period	320	269
Provision for loan losses	(13)	(37)
Balance, end of period	333	306
Ending balance: individually evaluated for impairment	17		16
Ending balance: collectively evaluated for impairment	316		304
Loans
Ending balance	64,548		51,966
Ending balance individually evaluated for impairment	635		282
Ending balance: collectively evaluated for impairment	63,913		51,684
Consumer and margin loans
Allowance for loan losses
Balance, beginning of period	257	102
Provision for loan losses	(23)	16
Loans charged to the allowance	(17)
Recoveries of loans previously charged off	4	34
Balance, end of period	267	$ 120
Ending balance: individually evaluated for impairment	146		146
Ending balance: collectively evaluated for impairment	121		111
Loans
Ending balance	11,229		9,420
Ending balance individually evaluated for impairment	146		146
Ending balance: collectively evaluated for impairment	$ 11,083		$ 9,274

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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- Definition

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.

+ References

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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 of expense related to estimated loss from loan and lease transactions.

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