Allowance for Probable Loan Losses (By Loan Class) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Allowance for probable loan losses
Balance at the beginning of the period	$ 62,033	$ 60,538	$ 66,988	$ 64,828
Losses charged to allowance	(4,188)	(5,167)	(31,298)	(22,196)
Recoveries credited to allowance	7,472	1,057	13,396	3,652
Net (losses) recoveries charged to allowance	3,284	(4,110)	(17,902)	(18,544)
Provision charged to operations	(1,347)	8,832	14,884	18,976
Balance at the end of the period	63,970	65,260	63,970	65,260
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	25,982	18,902	21,431	22,352
Losses charged to allowance	(3,485)	(4,921)	(27,952)	(20,303)
Recoveries credited to allowance	791	770	6,447	2,100
Net (losses) recoveries charged to allowance	(2,694)	(4,151)	(21,505)	(18,203)
Provision charged to operations	2,602	5,774	25,964	16,376
Balance at the end of the period	25,890	20,525	25,890	20,525
Commercial Real Estate: Other Construction and Land Development
Allowance for probable loan losses
Balance at the beginning of the period	11,109	13,524	13,920	12,955
Losses charged to allowance	(14)	(10)	(16)	(695)
Recoveries credited to allowance	6,073	98	6,080	137
Net (losses) recoveries charged to allowance	6,059	88	6,064	(558)
Provision charged to operations	(4,659)	654	(7,475)	1,869
Balance at the end of the period	12,509	14,266	12,509	14,266
Commercial Real Estate: Farmland & Commercial
Allowance for probable loan losses
Balance at the beginning of the period	16,942	17,885	19,769	18,683
Losses charged to allowance	(497)		(2,387)	(356)
Recoveries credited to allowance	512	7	598	820
Net (losses) recoveries charged to allowance	15	7	(1,789)	464
Provision charged to operations	291	1,733	(732)	478
Balance at the end of the period	17,248	19,625	17,248	19,625
Commercial Real Estate: Multifamily
Allowance for probable loan losses
Balance at the beginning of the period	855	685	1,248	846
Losses charged to allowance			(180)
Net (losses) recoveries charged to allowance			(180)
Provision charged to operations	(65)	120	(278)	(41)
Balance at the end of the period	790	805	790	805
Residential First Lien
Allowance for probable loan losses
Balance at the beginning of the period	2,277	3,434	3,509	3,589
Losses charged to allowance	(27)	(45)	(57)	(136)
Recoveries credited to allowance	11	4	18	28
Net (losses) recoveries charged to allowance	(16)	(41)	(39)	(108)
Provision charged to operations	126	287	(1,083)	199
Balance at the end of the period	2,387	3,680	2,387	3,680
Residential Junior Lien
Allowance for probable loan losses
Balance at the beginning of the period	3,400	4,308	5,321	4,683
Losses charged to allowance		(60)	(324)	(162)
Recoveries credited to allowance	74	155	188	406
Net (losses) recoveries charged to allowance	74	95	(136)	244
Provision charged to operations	221	130	(1,490)	(394)
Balance at the end of the period	3,695	4,533	3,695	4,533
Consumer
Allowance for probable loan losses
Balance at the beginning of the period	532	625	638	660
Losses charged to allowance	(124)	(131)	(341)	(544)
Recoveries credited to allowance	11	21	53	151
Net (losses) recoveries charged to allowance	(113)	(110)	(288)	(393)
Provision charged to operations	98	127	167	375
Balance at the end of the period	517	642	517	642
Foreign
Allowance for probable loan losses
Balance at the beginning of the period	936	1,175	1,152	1,060
Losses charged to allowance	(41)		(41)
Recoveries credited to allowance		2	12	10
Net (losses) recoveries charged to allowance	(41)	2	(29)	10
Provision charged to operations	39	7	(189)	114
Balance at the end of the period	$ 934	$ 1,184	$ 934	$ 1,184

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

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

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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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-Name Accounting Standards Codification
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Amount of expense related to estimated loss from loan and lease transactions.

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