Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Mortgage Servicing Rights (MSR) Impairment (Recovery)	$ (10,239)	$ 17,029
Mortgage servicing rights	48,378		$ 41,990
Equity securities	14,000		13,000
Investment securities gains (losses), net	17,144		15,106
Fair Value, Inputs, Level 3
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Equity securities	13,958		13,444
Investment securities gains (losses), net	13,958		13,444
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 2
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Write-down or Reserve, Amount	4,567		3,747
OREO(b)	14,197		6,125
Fair Value, Nonrecurring [Member] \| Fair Value, Inputs, Level 3
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Individually evaluated loans(a)	81,668		138,752
Provision for credit losses	(3,230)		97,519
Mortgage Servicing Rights (MSR) Impairment (Recovery)	10,239		(17,704)
Mortgage servicing rights	$ 48,378		$ 41,990

Other real estate owned fair value disclosure.

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Provision for Credit Losses, Impaired Loans

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- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI) and investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
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Amount of investment in equity security without readily determinable fair value.

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-Publisher FASB
-Name Accounting Standards Codification
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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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The adjustment to the carrying value of the rights retained or purchased to service mortgages. These adjustments are made when the estimate of the fair value is changed. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount of write-down or reserve recognized in the income statement on real estate investments for entities with a substantial portion of business acquiring and holding investment real estate.

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-Publisher FASB
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Fair value of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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-Name Accounting Standards Codification
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