Estimated Fair Values (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Estimated Fair Values For Certain Financial Assets And Financial Liabilities

The table presents the carrying values and estimated fair values for financial instruments as of March 31, 2020 and December 31, 2019:

(Dollars in thousands)	March 31, 2020				December 31, 2019
	Carrying value		Fair value		Carrying value		Fair value
Cash and due from banks	$	454,220	$	454,220	$	376,719	$	376,719
Overnight investments	688,518		688,518		1,107,844		1,107,844
Investment in marketable equity securities	315,501		315,501		82,333		82,333
Investment securities available for sale	7,789,034		7,789,034		7,059,674		7,059,674
Investment securities held to maturity	740,662		753,178		30,996		30,996
Loans held for sale	76,347		76,347		67,869		67,869
Net loans and leases	29,031,700		29,565,373		28,656,355		28,878,550
Income earned not collected	125,626		125,626		123,154		123,154
Federal Home Loan Bank stock	51,087		51,087		43,039		43,039
Mortgage and other servicing rights	21,488		22,733		24,891		26,927
Deposits	35,346,711		35,382,365		34,431,236		34,435,789
Securities sold under customer repurchase agreements	540,362		540,362		442,956		442,956
Federal Home Loan Bank borrowings	792,684		829,785		572,185		577,362
Subordinated debt	504,145		467,612		163,412		173,685
Other borrowings	105,303		105,460		148,318		149,232
FDIC shared-loss payable	14,737		15,674		112,395		114,252
Accrued interest payable	13,500		13,500		18,124		18,124

Assets And Liabilities Carried At Fair Value On A Recurring Basis

For assets and liabilities carried at fair value on a recurring basis, the following table provides fair value information as of March 31, 2020 and December 31, 2019:

	March 31, 2020
			Fair value measurements using:
(Dollars in thousands)	Fair value		Level 1 inputs		Level 2 inputs		Level 3 inputs
Assets measured at fair value
Investment securities available for sale
U.S. Treasury	$	205,782	$	—	$	205,782	$	—
Government agency	760,431		—		760,431		—
Residential mortgage-backed securities	5,952,841		—		5,952,841		—
Commercial mortgage-backed securities	650,565		—		650,565		—
Corporate bonds	219,415		—		152,399		67,016
Total investment securities available for sale	$	7,789,034	$	—	$	7,722,018	$	67,016
Marketable equity securities	$	315,501	$	111,807	$	203,694	$	—
Loans held for sale	$	76,347	$	—	$	76,347	$	—
	December 31, 2019
			Fair value measurements using:
	Fair value		Level 1 inputs		Level 2 inputs		Level 3 inputs
Assets measured at fair value
Investment securities available for sale
U.S. Treasury	$	409,999	$	—	$	409,999	$	—
Government agency	682,772		—		682,772		—
Residential mortgage-backed securities	5,267,090		—		5,267,090		—
Commercial mortgage-backed securities	380,020		—		380,020		—
Corporate bonds	201,566		—		131,881		69,685
State, county and municipal	118,227		—		118,227		—
Total investment securities available for sale	$	7,059,674	$	—	$	6,989,989	$	69,685
Marketable equity securities	$	82,333	$	29,458	$	52,875	$	—
Loans held for sale	$	67,869	$	—	$	67,869	$	—

Fair Value of Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

The following tables summarize activity for Level 3 assets:

	Three months ended March 31, 2020
(Dollars in thousands)	Corporate bonds
Balance at January 1, 2020	$	69,685
Unrealized net losses included in other comprehensive income	(4,366		)
Amounts included in net income	(85		)
Transfers in	1,782
Balance at March 31, 2020	$	67,016

Fair Value Level 3 Significant Unobservable Input Assumptions

(Dollars in thousands)			March 31, 2020
Level 3 assets	Valuation technique	Significant unobservable input	Fair Value
Corporate bonds	Indicative bid provided by broker	Multiple factors, including but not limited to, current operations, financial condition, cash flows, and recently executed financing transactions related to the issuer	$	67,016

Fair Value Option

The following table summarizes the difference between the aggregate fair value and the aggregate unpaid principal balance for residential real estate originated for sale measured at fair value as of March 31, 2020 and December 31, 2019:

	March 31, 2020
(Dollars in thousands)	Fair value		Aggregate unpaid principal balance		Difference
Originated loans held for sale	$	76,347	$	72,883	$	3,464
	December 31, 2019
	Fair value		Aggregate unpaid principal balance		Difference
Originated loans held for sale	$	67,869	$	65,697	$	2,172

No originated loans held for sale were 90 or more days past due or on nonaccrual status as of March 31, 2020 or December 31, 2019.

We may be required to measure certain financial assets at fair value on a nonrecurring basis. These adjustments to fair value usually result from the application of lower of amortized cost or fair value accounting or write-downs of individual assets due to impairment.

Following the adoption of ASC 326, the population of loans measured at fair value on a non-recurring basis has greatly diminished and is limited to collateral-dependent loans evaluated individually. These collateral-dependent loans are deemed to be at fair value if there is an associated allowance for credit losses or if a charge-off has been recorded in the previous 12 months. Collateral values are determined using appraisals or other third-party value estimates of the subject property discounted based on estimated selling costs, generally between 9% and 11%, and immaterial adjustments for other external factors that may impact the marketability of the collateral. The weighted average discount for estimated selling costs applied was 9.45%.

Prior to the adoption of ASC 326, impaired loans were deemed to be at fair value if an associated allowance or current period charge-off had been recorded. The value of impaired loans was determined by either collateral valuations or discounted present value of the expected cash flow calculations. Collateral values were determined using appraisals or other third-party value estimates of the subject property with discounts, generally between 6% and 11%, applied for estimated selling costs and other external factors that may impact the marketability of the property. Expected cash flows were determined using expected payment information at the individual loan level, discounted using the effective interest rate. The effective interest rate for the majority of impaired loans generally ranges between 3% and 7%.

OREO acquired or written down within the previous 12 months is deemed to be at fair value. Asset valuations are determined by using appraisals or other third-party value estimates of the subject property with with discounts generally between 7% and 22% applied for estimated selling costs and other external factors that may impact the marketability of the property. At March 31, 2020, the weighted average discount applied was 8.37%. Changes to the value of the assets between scheduled valuation dates are monitored through continued communication with brokers and monthly reviews by the asset manager assigned to each asset. If there are any significant changes in the market or the subject property, valuations are adjusted or new appraisals ordered to ensure the reported values reflect the most current information.

Assets And Liabilities Carried At Fair Value On A Nonrecurring Basis

For financial assets and liabilities carried at fair value on a nonrecurring basis, the following table provides fair value information as of March 31, 2020 and December 31, 2019:

	March 31, 2020
			Fair value measurements using:
(Dollars in thousands)	Fair value		Level 1 inputs		Level 2 inputs		Level 3 inputs
Collateral-dependent loans	$	5,489	$	—	$	—	$	5,489
Other real estate owned	46,710		—		—		46,710
Mortgage servicing rights	19,068		—		—		19,068
	December 31, 2019
			Fair value measurements using:
	Fair value		Level 1 inputs		Level 2 inputs		Level 3 inputs
Impaired loans	$	132,336	$	—	$	—	$	132,336
Other real estate owned	38,310		—		—		38,310
Mortgage servicing rights	3,757		—		—		3,757