Allowance for Probable Loan Losses (By Loan Class) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Allowance for probable loan losses
Balance at the beginning of the period	$ 64,661	$ 66,988
Losses charged to allowance	(2,992)	(19,575)
Recoveries credited to allowance	817	5,237
Net (losses) recoveries charged to allowance	(2,175)	(14,338)
Provision charged to operations	1,700	9,134
Balance at the end of the period	$ 64,186	61,784
Period of time for determining the historical charge-off experience	3 months
Watch - List Impaired
Allowance for probable loan losses
Losses charged to allowance		(16,800)
Commercial
Allowance for probable loan losses
Balance at the beginning of the period	$ 25,649	21,431
Losses charged to allowance	(2,735)	(19,071)
Recoveries credited to allowance	699	5,143
Net (losses) recoveries charged to allowance	(2,036)	(13,928)
Provision charged to operations	2,240	18,280
Balance at the end of the period	25,853	25,783
Commercial Real Estate: Other Construction and Land Development
Allowance for probable loan losses
Balance at the beginning of the period	13,889	13,920
Recoveries credited to allowance	1	4
Net (losses) recoveries charged to allowance	1	4
Provision charged to operations	(101)	(3,054)
Balance at the end of the period	13,789	10,870
Commercial Real Estate: Farmland & Commercial
Allowance for probable loan losses
Balance at the beginning of the period	16,731	19,769
Losses charged to allowance		(47)
Recoveries credited to allowance	58	11
Net (losses) recoveries charged to allowance	58	(36)
Provision charged to operations	(68)	(2,759)
Balance at the end of the period	16,721	16,974
Commercial Real Estate: Multifamily
Allowance for probable loan losses
Balance at the beginning of the period	806	1,248
Losses charged to allowance		(180)
Net (losses) recoveries charged to allowance		(180)
Provision charged to operations	12	(158)
Balance at the end of the period	818	910
Residential First Lien
Allowance for probable loan losses
Balance at the beginning of the period	2,455	3,509
Losses charged to allowance	(31)	(7)
Recoveries credited to allowance	5	3
Net (losses) recoveries charged to allowance	(26)	(4)
Provision charged to operations	(38)	(1,136)
Balance at the end of the period	2,391	2,369
Residential Junior Lien
Allowance for probable loan losses
Balance at the beginning of the period	3,716	5,321
Losses charged to allowance	(105)	(169)
Recoveries credited to allowance	24	38
Net (losses) recoveries charged to allowance	(81)	(131)
Provision charged to operations	(449)	(1,770)
Balance at the end of the period	3,186	3,420
Consumer
Allowance for probable loan losses
Balance at the beginning of the period	531	638
Losses charged to allowance	(121)	(101)
Recoveries credited to allowance	16	37
Net (losses) recoveries charged to allowance	(105)	(64)
Provision charged to operations	78	(44)
Balance at the end of the period	504	530
Foreign
Allowance for probable loan losses
Balance at the beginning of the period	884	1,152
Recoveries credited to allowance	14	1
Net (losses) recoveries charged to allowance	14	1
Provision charged to operations	26	(225)
Balance at the end of the period	$ 924	$ 928

Period of time that is used to determine the historical charge-off experience.

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- Definition

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

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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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- Definition

Amount, after recoveries, of loans and leases that have been written-off.

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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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- Definition

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

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