Consolidated Balance Sheets (unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 292,168	$ 175,542
Accounts receivable and unbilled revenues, net	255,365	313,696
Available-for-sale investment securities, at fair value	590,648	550,394
Stock in Federal Home Loan Bank of Seattle, at cost	63,711	69,302
Loans receivable held for investment, net	4,401,504	4,389,033
Loans held for sale, at lower of cost or fair value	9,906	8,424
Property, plant and equipment, net of accumulated depreciation of $2,258,065 and $2,250,950 at the respective dates	4,190,835	4,148,774
Regulatory assets	905,589	905,264
Other	481,531	542,523
Goodwill	82,190	82,190
Total assets	11,273,447	11,185,142
Liabilities
Accounts payable	167,784	186,425
Interest and dividends payable	25,225	25,336
Deposit liabilities	4,751,328	4,623,415
Short-term borrowings—other than bank	30,500	118,972
Other bank borrowings	312,094	290,656
Long-term debt, net—other than bank	1,506,546	1,506,546
Deferred income taxes	640,778	633,570
Regulatory liabilities	351,712	344,849
Contributions in aid of construction	474,385	466,432
Defined benefit pension and other postretirement benefit plans liability	624,555	632,845
Other	456,338	531,230
Total liabilities	9,341,245	9,360,276
Preferred stock of subsidiaries - not subject to mandatory redemption	34,293	34,293
Commitments and contingencies
Shareholders’ equity
Preferred stock, no par value, authorized 10,000,000 shares; issued: none	0	0
Common stock, no par value, authorized 200,000,000 shares; issued and outstanding: 107,417,644 shares and 102,565,266 shares at the respective dates	1,624,549	1,521,297
Retained earnings	296,680	296,654
Accumulated other comprehensive loss, net of tax benefits	(23,320)	(27,378)
Total shareholders’ equity	1,897,909	1,790,573
Total liabilities and shareholders’ equity	$ 11,273,447	$ 11,185,142