Borrowings (Tables) - Debt Instrument [Domain]

6 Months Ended

Jun. 30, 2018

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

(In thousands)	June 30, 2018		December 31, 2017
Assets sold under agreements to repurchase	$	306,911	$	390,921
Total assets sold under agreements to repurchase	$	306,911	$	390,921

Schedule of Repurchase Agreements [Table Text Block]

		June 30, 2018		December 31, 2017
			Repurchase		Repurchase
(In thousands)			liability		liability
U.S. Treasury securities
	Within 30 days	$	147,318	$	148,516
	After 30 to 90 days		64,413		87,357
	After 90 days		46,703		43,500
Total U.S. Treasury securities			258,434		279,373
Obligations of U.S. government sponsored entities
	Within 30 days		5,152		30,656
	After 30 to 90 days		5,000		19,463
	After 90 days		6,000		15,937
Total obligations of U.S. government sponsored entities			16,152		66,056
Mortgage-backed securities
	Within 30 days		22,642		31,383
Total mortgage-backed securities			22,642		31,383
Collateralized mortgage obligations
	Within 30 days		9,683		14,109
Total collateralized mortgage obligations			9,683		14,109
Total		$	306,911	$	390,921

Schedule of Short-term Debt [Table Text Block]

(In thousands)	June 30, 2018		December 31, 2017
Advances with the FHLB	$	-	$	95,000
Others		1,200		1,208
Total other short-term borrowings	$	1,200	$	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)		June 30, 2018		December 31, 2017
Advances with the FHLB with maturities ranging from 2018 through 2029 paying interest at
	monthly fixed rates ranging from 0.89% to 4.19 %	$	602,262	$	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 0.12% to 0.24% over the 3 month LIBOR		19,724		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 $2,085		447,915		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 $436		439,364		439,351
Others			18,234		18,642
Total notes payable		$	1,561,663	$	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	$	300,911	$	1,200	$	139,597	$	441,708
2019		6,000		-		649,793		655,793
2020		-		-		112,035		112,035
2021		-		-		21,877		21,877
2022		-		-		105,175		105,175
Later years		-		-		533,186		533,186
Total borrowings	$	306,911	$	1,200	$	1,561,663	$	1,869,774