Note 17 - Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2014

Fair Value Disclosures [Abstract]

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

	December 31, 2014				December 31, 2013
	Carrying				Carrying
	Amount		Fair Value		Amount		Fair Value
	(In thousands)
Financial Assets
Cash and due from banks	$	176,830	$	176,830	$	153,747	$	153,747
Short-term investments		489,614		489,614		516,938		516,938
Securities available-for-sale		1,318,935		1,318,935		1,586,668		1,586,668
Trading securities		-		-		4,936		4,936
Loans held for sale		973		1,225		-		-
Loans, net		8,740,268		8,688,072		7,897,187		7,760,490
Investment in Federal Home Loan Bank stock		30,785		30,785		25,000		25,000
Warrants		27		27		30		30

	Notional				Notional
	Amount		Fair Value		Amount		Fair Value
Option contracts	$	-	$	-	$	200	$	0
Foreign exchange contracts		167,005		1,876		267,644		6,182

	Carrying				Carrying
	Amount		Fair Value		Amount		Fair Value
Financial Liabilities
Deposits	$	8,783,460	$	8,785,342	$	7,981,305	$	7,977,639
Securities sold under agreements to repurchase		450,000		473,816		800,000		852,835
Advances from Federal Home Loan Bank		425,000		424,974		521,200		521,560
Other borrowings		19,934		17,978		19,062		16,107
Long-term debt		119,136		59,425		121,136		58,970

	Notional				Notional
	Amount		Fair Value		Amount		Fair Value
Foreign exchange contracts	$	178,868	$	5,007	$	236,350	$	6,140
Interest rate swaps		300,480		4,626		-		-

	Notional					Notional
	Amount		Fair Value			Amount		Fair Value
Off-Balance Sheet Financial Instruments
Commitments to extend credit	$	2,071,766	$	(3,442	)	$	1,858,669	$	(2,187	)
Standby letters of credit		53,910		(243	)		45,058		(205	)
Other letters of credit		48,142		(29	)		54,098		(34	)
Bill of lading guarantees		108		-			80		-

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

	As of December 31, 2014
	Estimated
	Fair Value
	Measurements		Level 1		Level 2		Level 3
	(In thousands)
Financial Assets
Cash and due from banks	$	176,830	$	176,830	$	-	$	-
Short-term investments		489,614		489,614		-		-
Securities available-for-sale		1,318,935		669,870		649,065		-
Loans held-for-sale		1,225		-		-		1,225
Loans, net		8,688,072		-		-		8,688,072
Investment in Federal Home Loan Bank stock		30,785		-		30,785		-
Warrants		27		-		-		27
Financial Liabilities
Deposits		8,785,342		-		-		8,785,342
Securities sold under agreement to repurchase		473,816		-		473,816		-
Advances from Federal Home Loan Bank		424,974		-		424,974		-
Other borrowings		17,978		-		-		17,978
Long-term debt		59,425		-		59,425		-

	As of December 31, 2013
	Estimated
	Fair Value
	Measurements		Level 1		Level 2		Level 3
	(In thousands)
Financial Assets
Cash and due from banks	$	153,747	$	153,747	$	-	$	-
Short-term investments		516,938		516,938		-		-
Securities available-for-sale		1,586,668		465,917		1,120,751		-
Trading securities		4,936		-		4,936		-
Loans, net		7,760,490		-		-		7,760,490
Investment in Federal Home Loan Bank stock		25,000		-		25,000		-
Warrants		30		-		-		30
Financial Liabilities
Deposits		7,977,639		-		-		7,977,639
Securities sold under agreement to repurchase		852,835		-		852,835		-
Advances from Federal Home Loan Bank		521,560		-		521,560		-
Other borrowings		16,107		-		-		16,107
Long-term debt		58,970		-		58,970		-