Note 15 - Fair Value Measurements and Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

As of December 31, 2020	Fair Value Measurements Using						Total at
	Level 1		Level 2		Level 3		Fair Value
	(In thousands)
Assets
Securities available-for-sale
U.S. Treasury securities	$	80,948	$	—	$	—	$	80,948
U.S. government agency entities		—		99,838		—		99,838
Mortgage-backed securities		—		727,068		—		727,068
Collateralized mortgage obligations		—		10,324		—		10,324
Corporate debt securities		—		118,372		—		118,372
Total securities available-for-sale		80,948		955,602		—		1,036,550
Equity securities
Mutual funds		6,413		—		—		6,413
Preferred stock of government sponsored entities		5,485		—		—		5,485
Other equity securities		11,846		—		—		11,846
Total equity securities		23,744		—		—		23,744
Warrants		—		—		21		21
Interest rate swaps		—		3,409		—		3,409
Foreign exchange contracts		—		4,658		—		4,658
Total assets	$	104,692	$	963,669	$	21	$	1,068,382
Liabilities
Interest rate swaps	$	—	$	10,286	$	—	$	10,286
Foreign exchange contracts		—		2,200		—		2,200
Total liabilities	$	—	$	12,486	$	—	$	12,486

As of December 31, 2019	Fair Value Measurements Using						Total at
	Level 1		Level 2		Level 3		Fair Value
	(In thousands)
Assets
Securities available-for-sale
U.S. Treasury securities	$	74,936	$	—	$	—	$	74,936
U.S. government agency entities		—		90,796		—		90,796
U.S. government sponsored entities		—		224,443		—		224,443
Mortgage-backed securities		—		887,790		—		887,790
Collateralized mortgage obligations		—		552		—		552
Corporate debt securities		—		173,325		—		173,325
Total securities available-for-sale		74,936		1,376,906		—		1,451,842
Equity securities
Mutual funds		6,277		—		—		6,277
Preferred stock of government sponsored entities		10,529		—		—		10,529
Other equity securities		11,199		—		—		11,199
Total equity securities		28,005		—		—		28,005
Warrants		—		—		39		39
Interest rate swaps		—		2,181		—		2,181
Foreign exchange contracts		—		2,411		—		2,411
Total assets	$	102,941	$	1,381,498	$	39	$	1,484,478
Liabilities
Option contracts	$	—	$	7	$	—	$	7
Interest rate swaps		—		14,229		—		14,229
Foreign exchange contracts		—		1,415		—		1,415
Total liabilities	$	—	$	15,651	$	—	$	15,651

Fair Value Measurements, Nonrecurring [Table Text Block]

	As of December 31, 2020								Total Losses
	Fair Value Measurements Using								For the Twelve Months Ended
	Level 1		Level 2		Level 3		Total at Fair Value		December 31, 2020		December 31, 2019
	(In thousands)
Assets
Impaired loans by type:
Commercial loans	$	—	$	—	$	5,342	$	5,342	$	7,012	$	—
Commercial mortgage loans		—		—		25,749		25,749		—		—
Residential mortgage and equity lines		—		—		4,307		4,307		—		—
Total impaired loans		—		—		35,398		35,398		7,012		—
Other real estate owned (1)		—		905		4,236		5,141		717		681
Investments in venture capital		—		—		1,381		1,381		107		167
Total assets	$	—	$	905	$	41,015	$	41,920	$	7,836	$	848

	As of December 31, 2019								Total Losses/(Gains)
	Fair Value Measurements Using								For the Twelve Months Ended
	Level 1		Level 2		Level 3		Total at Fair Value		December 31, 2019		December 31, 2018
	(In thousands)
Assets
Impaired loans by type:
Commercial loans	$	—	$	—	$	6,196	$	6,196	$	—	$	—
Commercial mortgage loans		—		—		25,566		25,566		—		—
Residential mortgage and equity lines		—		—		5,320		5,320		—		—
Total impaired loans		—		—		37,082		37,082		—		—
Other real estate owned (1)		—		6,490		4,343		10,833		681		(619	)
Investments in venture capital		—		—		1,604		1,604		167		330
Total assets	$	—	$	6,490	$	43,029	$	49,519	$	848	$	(289	)

Fair Value, by Balance Sheet Grouping [Table Text Block]

	December 31, 2020				December 31, 2019
	Carrying				Carrying
	Amount		Fair Value		Amount		Fair Value
	(In thousands)
Financial Assets
Cash and due from banks	$	138,616	$	138,616	$	177,240	$	177,240
Short-term investments		1,282,462		1,282,462		416,538		416,538
Securities available-for-sale		1,036,550		1,036,550		1,451,842		1,451,842
Loans, net		15,475,364		16,103,471		14,951,631		15,444,752
Equity securities		23,744		23,744		28,005		28,005
Investment in Federal Home Loan Bank stock		17,250		17,250		18,090		18,090
Warrants		21		21		39		39

	Notional				Notional
	Amount		Fair Value		Amount		Fair Value
Foreign exchange contracts	$	151,244	$	4,658	$	146,397	$	2,411
Interest rate swaps		96,889		3,409		130,401		2,181

Financial Liabilities	Carrying				Carrying
	Amount		Fair Value		Amount		Fair Value
Deposits	$	16,109,401	$	16,125,808	$	14,692,308	$	14,719,452
Short-term borrowings		—		—		25,683		25,683
Advances from Federal Home Loan Bank		150,000		155,133		670,000		674,530
Other borrowings		23,714		19,632		36,666		30,764
Long-term debt		119,136		65,487		119,136		76,058

	Notional				Notional
	Amount		Fair Value		Amount		Fair Value
Option contracts	$	—	$	—	$	908	$	7
Foreign exchange contracts		132,813		2,200		127,003		1,415
Interest rate swaps		679,648		10,286		602,291		14,229

	Notional					Notional
	Amount		Fair Value			Amount		Fair Value
Off-Balance Sheet Financial Instruments
Commitments to extend credit	$	2,977,528	$	(8,432	)	$	3,077,081	$	(9,826	)
Standby letters of credit		234,200		(1,630	)		282,352		(2,431	)
Other letters of credit		16,821		(16	)		22,209		(20	)
Bill of lading guarantees		238		—			319		(1	)

Schedule Of Fair Value Of Financial Instruments [Table Text Block]

	As of December 31, 2020
	Estimated
	Fair Value
	Measurements		Level 1		Level 2		Level 3
	(In thousands)
Financial Assets
Cash and due from banks	$	138,616	$	138,616	$	—	$	—
Short-term investments		1,282,462		1,282,462		—		—
Securities available-for-sale		1,036,550		80,948		955,602		—
Loans, net		16,103,471		—		—		16,103,471
Equity securities		23,744		23,744		—		—
Investment in Federal Home Loan Bank stock		17,250		—		17,250		—
Warrants		21		—		—		21
Financial Liabilities
Deposits		16,125,808		—		—		16,125,808
Advances from Federal Home Loan Bank		155,133		—		155,133		—
Other borrowings		19,632		—		—		19,632
Long-term debt		65,487		—		65,487		—

	As of December 31, 2019
	Estimated
	Fair Value
	Measurements		Level 1		Level 2		Level 3
	(In thousands)
Financial Assets
Cash and due from banks	$	177,240	$	177,240	$	—	$	—
Short-term investments		416,538		416,538		—		—
Securities available-for-sale		1,451,842		74,936		1,376,906		—
Loans, net (1)		15,444,752		—		—		15,444,752
Equity securities		28,005		28,005		—		—
Investment in Federal Home Loan Bank stock		18,090		—		18,090		—
Warrants		39		—		—		39
Financial Liabilities
Deposits		14,719,452		—		—		14,719,452
Short-term borrowings		25,683		—		—		25,683
Advances from Federal Home Loan Bank		674,530		—		674,530		—
Other borrowings		30,764		—		—		30,764
Long-term debt		76,058		—		76,058		—