Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities
Net income	$ 88,294	$ 75,213
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation of property, plant and equipment	86,397	79,843
Other amortization	4,014	2,868
Provision for loan losses	2,016	899
Loans receivable originated and purchased, held for sale	(69,656)	(128,276)
Proceeds from sale of loans receivable, held for sale	75,040	148,243
Increase in deferred income taxes	28,252	40,403
Excess tax benefits from share-based payment arrangements	(267)	(445)
Allowance for equity funds used during construction	(2,996)	(2,775)
Change in cash overdraft	(1,038)	0
Changes in assets and liabilities
Decrease (increase) in accounts receivable and unbilled revenues, net	(2,986)	3,564
Decrease (increase) in fuel oil stock	(27,206)	43,974
Increase in regulatory assets	(17,731)	(37,586)
Decrease in accounts, interest and dividends payable	(64,843)	(43,384)
Change in prepaid and accrued income taxes and utility revenue taxes	(32,510)	(33,822)
Decrease in defined benefit pension and other postretirement benefit plans liability	(1,714)	(330)
Change in other assets and liabilities	(16,871)	(17,597)
Net cash provided by operating activities	46,195	130,792
Cash flows from investing activities
Available-for-sale investment and mortgage-related securities purchased	(125,531)	(39,721)
Principal repayments on available-for-sale investment and mortgage-related securities	33,202	62,819
Proceeds from sale of available-for-sale investment securities	79,564	71,367
Redemption of stock from Federal Home Loan Bank of Seattle	11,683	1,742
Net increase in loans held for investment	(137,122)	(201,184)
Proceeds from sale of real estate acquired in settlement of loans	2,162	5,712
Capital expenditures	(149,253)	(158,830)
Contributions in aid of construction	13,209	17,188
Other	(16)	622
Net cash used in investing activities	(272,102)	(240,285)
Cash flows from financing activities
Net increase in deposit liabilities	152,383	46,326
Net increase in short-term borrowings with original maturities of three months or less	79,693	42,093
Net decrease in retail repurchase agreements	(2,053)	(8,054)
Proceeds from other bank borrowings	0	25,000
Repayments of other bank borrowings	0	(25,000)
Proceeds from issuance of long-term debt	125,000	50,000
Repayment of long-term debt	(100,000)	(50,000)
Excess tax benefits from share-based payment arrangements	267	445
Net proceeds from issuance of common stock	3,048	11,994
Common stock dividends	(62,892)	(48,921)
Preferred stock dividends of subsidiaries	(946)	(946)
Other	(252)	606
Net cash provided by financing activities	194,248	43,543
Net decrease in cash and cash equivalents	(31,659)	(65,950)
Cash and cash equivalents, beginning of period	220,036	219,662
Cash and cash equivalents, end of period	$ 188,377	$ 153,712