Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities
Net income	$ 38,789	$ 28,935
Adjustments to reconcile net income to net cash used in operating activities
Depreciation of property, plant and equipment	37,911	37,708
Other amortization	1,419	2,354
Provision for loan losses	3,546	4,550
Loans receivable originated and purchased, held for sale	(89,087)	(35,015)
Proceeds from sale of loans receivable, held for sale	85,252	43,048
Change in deferred income taxes	21,260	16,687
Change in excess tax benefits from share-based payment arrangements	(44)	(22)
Allowance for equity funds used during construction	(1,940)	(1,244)
Change in cash overdraft		(2,688)
Changes in assets and liabilities
Decrease (increase) in accounts receivable and unbilled revenues, net	37,562	(19,880)
Increase in fuel oil stock	(14,458)	(3,513)
Decrease in accounts, interest and dividends payable	(36,991)	(41,136)
Change in prepaid and accrued income taxes and utility revenue taxes	(41,126)	(1,594)
Contributions to defined benefit pension and other postretirement benefit plans	(26,815)	(31,200)
Change in other assets and liabilities	(30,994)	(10,224)
Net cash used in operating activities	(15,716)	(13,234)
Cash flows from investing activities
Available-for-sale investment and mortgage-related securities purchased	(53,931)	(109,307)
Principal repayments on available-for-sale investment and mortgage-related securities	46,355	114,529
Net increase in loans held for investment	(34,212)	(70,269)
Proceeds from sale of real estate acquired in settlement of loans	3,371	1,253
Capital expenditures	(65,300)	(38,491)
Contributions in aid of construction	22,855	5,749
Other		145
Net cash used in investing activities	(80,862)	(96,391)
Cash flows from financing activities
Net increase in deposit liabilities	55,172	59,883
Net increase (decrease) in short-term borrowings with original maturities of three months or less	87,467	(24,923)
Net increase (decrease) in retail repurchase agreements	(379)	7,368
Proceeds from issuance of long-term debt		125,000
Repayment of long-term debt	(57,500)	(50,000)
Change in excess tax benefits from share-based payment arrangements	44	22
Net proceeds from issuance of common stock	5,940	5,674
Common stock dividends	(23,855)	(23,593)
Preferred stock dividends of subsidiaries	(473)	(473)
Other	(3,757)	(3,730)
Net cash provided by financing activities	62,659	95,228
Net decrease in cash and cash equivalents	(33,919)	(14,397)
Cash and cash equivalents, beginning of period	270,265	330,651
Cash and cash equivalents, end of period	$ 236,346	$ 316,254