Borrowings (Tables) - Debt Instrument [Domain]

3 Months Ended

Mar. 31, 2018

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

(In thousands)	March 31, 2018		December 31, 2017
Assets sold under agreements to repurchase	$	380,061	$	390,921
Total assets sold under agreements to repurchase	$	380,061	$	390,921

Schedule of Repurchase Agreements [Table Text Block]

		March 31, 2018		December 31, 2017
			Repurchase		Repurchase
(In thousands)			liability		liability
U.S. Treasury Securities
	Within 30 days	$	54,013	$	148,516
	After 30 to 90 days		53,921		87,357
	After 90 days		181,698		43,500
Total U.S. Treasury Securities			289,632		279,373
Obligations of U.S. government sponsored entities
	Within 30 days		62,098		30,656
	After 30 to 90 days		-		19,463
	After 90 days		-		15,937
Total obligations of U.S. government sponsored entities			62,098		66,056
Mortgage-backed securities
	Within 30 days		4,645		31,383
	After 90 days		13,085		-
Total mortgage-backed securities			17,730		31,383
Collateralized mortgage obligations
	Within 30 days		10,601		14,109
Total collateralized mortgage obligations			10,601		14,109
Total		$	380,061	$	390,921

Schedule of Short-term Debt [Table Text Block]

(In thousands)	March 31, 2018		December 31, 2017
Advances with the FHLB paying interest at maturity with fixed rates ranging from 1.63% to 2.02%	$	185,000	$	95,000
Others		1,200		1,208
Total other short-term borrowings	$	186,200	$	96,208
Note: Refer to the Corporation's 2017 Form 10-K for rates information at December 31, 2017.

Schedule of Notes Payable [Table Text Block]

(In thousands)		March 31, 2018		December 31, 2017
Advances with the FHLB with maturities ranging from 2018 through 2029 paying interest at
	monthly fixed rates ranging from 0.84% to 4.19 %	$	599,954	$	572,307
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		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		25,019		25,019
Unsecured senior debt securities maturing on 2019 paying interest semiannually at a
	fixed rate of 7.00%, net of debt issuance costs of $2,606		447,394		446,873
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 $443		439,357		439,351
Others			18,316		18,642
Total notes payable		$	1,564,204	$	1,536,356

Maturity Distribution Of Debt Securities [Text Block]

	Assets sold under			Short-term
(In thousands)	agreements to repurchase			borrowings	Notes payable		Total
2018	$	380,061	$	186,200	$	242,635	$	808,896
2019		-		-		649,382		649,382
2020		-		-		112,069		112,069
2021		-		-		21,840		21,840
2022		-		-		5,143		5,143
Later years		-		-		533,135		533,135
Total borrowings	$	380,061	$	186,200	$	1,564,204	$	2,130,465