Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities
Net income	$ 123,920	$ 126,239
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation of property, plant and equipment	120,355	112,946
Other amortization	2,352	4,811
Provision for loan losses	953	9,504
Loans receivable originated and purchased, held for sale	(199,772)	(304,289)
Proceeds from sale of loans receivable, held for sale	223,221	302,844
Gain on sale of credit card portfolio	(2,251)	0
Change in deferred income taxes	60,580	82,582
Excess tax benefits from share-based payment arrangements	(469)	(65)
Allowance for equity funds used during construction	(4,030)	(5,548)
Changes in assets and liabilities
Decrease (increase) in accounts receivable and unbilled revenues, net	12,740	(30,610)
Decrease (increase) in fuel oil stock	24,332	(31,372)
Increase in regulatory assets	(53,314)	(57,793)
Decrease in accounts, interest and dividends payable	(21,708)	(5,905)
Decrease in prepaid and accrued income taxes and utility revenue taxes	(19,212)	(5,121)
Contributions to defined benefit pension and other postretirement benefit plans	(62,279)	(64,006)
Other increase in defined benefit pension and other postretirement benefit plans liability	61,770	49,950
Change in other assets and liabilities	(20,462)	(62,563)
Net cash provided by (used in) operating activities	246,726	121,604
Cash flows from investing activities
Available-for-sale investment and mortgage-related securities purchased	(39,721)	(146,794)
Principal repayments on available-for-sale investment and mortgage-related securities	84,487	104,310
Proceeds from sale of available-for-sale investment and mortgage-related securities	71,367	3,548
Net increase in loans held for investment	(293,996)	(75,982)
Proceeds from sale of real estate acquired in settlement of loans	8,777	9,659
Capital expenditures	(247,392)	(225,961)
Contributions in aid of construction	23,633	33,106
Proceeds from sale of credit card portfolio	26,386	0
Other	3,035	865
Net cash used in investing activities	(363,424)	(297,249)
Cash flows from financing activities
Net increase in deposit liabilities	80,926	56,756
Net increase in short-term borrowings with original maturities of three months or less	47,648	13,398
Net decrease in retail repurchase agreements	(6,314)	(22,011)
Proceeds from other bank borrowings	120,000	0
Repayments of other bank borrowings	(70,000)	0
Proceeds from issuance of long-term debt	50,000	457,000
Repayment of long-term debt	(50,000)	(368,500)
Excess tax benefits from share-based payment arrangements	469	65
Net proceeds from issuance of common stock	18,383	16,881
Common stock dividends	(73,584)	(71,966)
Preferred stock dividends of subsidiaries	(1,417)	(1,417)
Other	(4,033)	(6,314)
Net cash provided by (used in) financing activities	112,078	73,892
Net decrease in cash and cash equivalents	(4,620)	(101,753)
Cash and cash equivalents, beginning of period	219,662	270,265
Cash and cash equivalents, end of period	$ 215,042	$ 168,512