Borrowings (Tables)

12 Months Ended

Dec. 31, 2017

Debt Instrument [Domain]

Schedule Of Fed Funds Purchased And Assets Sold Under Agreements To Repurchase Table [Text Block]

(In thousands)	December 31, 2017		December 31, 2016
Assets sold under agreements to repurchase	$	390,921	$	479,425
Total assets sold under agreements to repurchase	$	390,921	$	479,425

Schedule of Repurchase Agreements [Table Text Block]

		December 31, 2017				December 31, 2016
				Repurchase liability				Repurchase liability
			Repurchase	weighted average			Repurchase	weighted average
(Dollars in thousands)			liability	interest rate			liability	interest rate
U.S. Treasury Securities
	Within 30 days	$	148,516	1.70	%	$	32,700	0.85	%
	After 30 to 90 days		87,357	1.70			-	-
	After 90 days		43,500	2.00			19,819	1.61
Total U.S. Treasury Securities			279,373	1.75			52,519	1.14
Obligations of U.S. government
	sponsored entities
	Within 30 days		30,656	1.77			95,720	1.00
	After 30 to 90 days		19,463	1.48			142,299	0.91
	After 90 days		15,937	1.60			25,380	1.08
Total obligations of U.S. government sponsored entities			66,056	1.64			263,399	0.96
Mortgage-backed securities
	Within 30 days		31,383	1.51			39,108	1.05
	After 30 to 90 days		-	-			58,552	0.94
	After 90 days		-	-			54,560	1.09
Total mortgage-backed securities			31,383	1.51			152,220	1.02
Collateralized mortgage obligations
	Within 30 days		14,109	0.28			11,287	0.28
Total collateralized mortgage
	obligations		14,109	0.28			11,287	0.28
Total		$	390,921	1.66	%	$	479,425	0.98	%

Schedule of Notes Payable [Table Text Block]

(In thousands)		December 31, 2017		December 31, 2016
Advances with the FHLB with maturities ranging from 2018 through 2029 paying interest at
	monthly fixed rates ranging from 0.84% to 4.19 % (2016 - 0.81% to 4.19%)	$	572,307	$	608,193
Advances with the FHLB with maturities ranging from 2018 through 2019 paying interest monthly
	at a floating rate ranging from 0.22% to 0.34% over the 1 month LIBOR (2016 - 0.22% to 0.34%)		34,164		34,164
Advances with the FHLB with maturities ranging from 2018 through 2019 paying interest quarterly
	at a floating rate from 0.09% to 0.24% over the 3 month LIBOR (2016 - (0.01)% to 0.24%)		25,019		30,313
Unsecured senior debt securities maturing on 2019 paying interest semiannually at a
	fixed rate of 7.00%, net of debt issuance costs of $3,127 (2016 - $5,212)		446,873		444,788
Junior subordinated deferrable interest debentures (related to trust preferred securities)
	with maturities ranging from 2027 to 2034 with fixed interest rates ranging from
	6.125% to 8.327%, net of debt issuance costs of $449 (2016 - $476)		439,351		439,323
Others			18,642		18,071
Total notes payable		$	1,536,356	$	1,574,852

Maturity Distribution Of Debt Securities [Text Block]

	Assets sold under			Short-term
(In thousands)	agreements to repurchase			borrowings	Notes payable		Total
2018	$	390,921	$	96,200	$	255,088	$	742,209
2019		-		-		609,015		609,015
2020		-		-		112,144		112,144
2021		-		-		21,840		21,840
2022		-		-		5,143		5,143
Later years		-		-		533,126		533,126
No stated maturity		-		8		-		8
Total borrowings	$	390,921	$	96,208	$	1,536,356	$	2,023,485

Federal Funds Purchased And Securities Sold Under Agreements To Repurchase [Member]

Schedule Of Maximum Aggregate Balance Average Aggregate Balance And Weighted Average Interest Rate [Text Block]

Assets sold under agreements to repurchase:
(Dollars in thousands)			2017			2016
Maximum aggregate balance outstanding at any month-end		$	471,083		$	954,253
Average monthly aggregate balance outstanding		$	399,422		$	757,230
Weighted average interest rate:
	For the year		1.22	%		1.01	%
	At December 31		1.50	%		1.12	%

Short-term Debt [Member]

Schedule Of Maximum Aggregate Balance Average Aggregate Balance And Weighted Average Interest Rate [Text Block]

Other short-term borrowings:
(Dollars in thousands)			2017			2016
Advances with the FHLB paying interest at maturity raging from 1.43% to 1.66%		$	95,000		$	-
Others			1,208			1,200
Balance outstanding at the end of the period		$	96,208		$	1,200
Maximum aggregate balance outstanding at any month-end		$	240,598		$	31,200
Average monthly aggregate balance outstanding		$	52,784		$	6,266
Weighted average interest rate:
	For the year		1.61	%		2.15	%
	At December 31		1.55	%		9.00	%