Note 12 - Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Disclosures [Abstract]

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

	March 31, 2016				December 31, 2015
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(In thousands)
Financial Assets
Cash and due from banks	$	192,642	$	192,642	$	180,130	$	180,130
Short-term investments		432,384		432,384		536,880		536,880
Securities available-for-sale		1,485,124		1,485,124		1,586,352		1,586,352
Loans held for sale		-		-		6,676		6,676
Loans, net		10,221,510		10,142,747		10,016,227		9,938,810
Investment in Federal Home Loan Bank stock		17,250		17,250		17,250		17,250
Warrants		94		94		62		62

	Notional Amount		Fair Value		Notional Amount		Fair Value
Foreign exchange contracts	$	138,201	$	3,314	$	100,602	$	3,339

	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Financial Liabilities
Deposits	$	10,324,116	$	10,331,030	$	10,509,087	$	10,509,879
Securities sold under agreements to repurchase		400,000		413,195		400,000		413,417
Advances from Federal Home Loan Bank		475,000		475,128		275,000		274,488
Other borrowings		17,792		15,478		18,593		16,684
Long-term debt		119,136		58,951		119,136		58,420

	Notional Amount		Fair Value		Notional Amount		Fair Value
Option contracts	$	-	$	-	$	9,396	$	28
Foreign exchange contracts		73,006		913		115,418		4,124
Interest rate swaps		476,590		14,878		459,416		6,496

	Notional Amount		Fair Value			Notional Amount		Fair Value
Off-Balance Sheet Financial Instruments
Commitments to extend credit	$	2,098,360	$	(5,722	)	$	1,971,848	$	(5,570	)
Standby letters of credit		49,334		(199	)		49,081		(194	)
Other letters of credit		30,883		(18	)		38,131		(22	)
Bill of lading guarantees		52		-			454		(1	)

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

	March 31, 2016
	Estimated Fair Value Measurements		Level 1		Level 2		Level 3
	(In thousands)
Financial Assets
Cash and due from banks	$	192,642	$	192,642	$	-	$	-
Short-term investments		432,384		432,384		-		-
Securities available-for-sale		1,485,124		230,719		1,254,405		-
Loans, net		10,142,747		-		-		10,142,747
Investment in Federal Home Loan Bank stock		17,250		-		17,250		-
Warrants		94		-		-		94
Financial Liabilities
Deposits		10,331,030		-		-		10,331,030
Securities sold under agreements to repurchase		413,195		-		413,195		-
Advances from Federal Home Loan Bank		475,128		-		475,128		-
Other borrowings		15,478		-		-		15,478
Long-term debt		58,951		-		58,951		-

	December 31, 2015
	Estimated Fair Value Measurements		Level 1		Level 2		Level 3
	(In thousands)
Financial Assets
Cash and due from banks	$	180,130	$	180,130	$	-	$	-
Short-term investments		536,880		536,880		-		-
Securities available-for-sale		1,586,352		290,121		1,296,231		-
Loans held-for-sale		6,676		-		-		6,676
Loans, net		9,938,810		-		-		9,938,810
Investment in Federal Home Loan Bank stock		17,250		-		17,250		-
Warrants		62		-		-		62
Financial Liabilities
Deposits		10,509,879		-		-		10,509,879
Securities sold under agreements to repurchase		413,417		-		413,417		-
Advances from Federal Home Loan Bank		274,488		-		-		274,488
Other borrowings		16,684		-		-		16,684
Long-term debt		58,420		-		58,420		-