CONDENCED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Utility Plant
Plant in Service	$ 4,675,441	$ 4,467,667
Utility Plant Under Capital Leases	747,158	637,957
Construction Work in Progress	173,022	180,485
Total Utility Plant	5,595,621	5,286,109
Less Accumulated Depreciation and Amortization	(1,909,448)	(1,826,977)
Less Accumulated Amortization of Capital Lease Assets	(531,159)	(514,677)
Total Utility Plant—Net	3,155,014	2,944,455
Investments and Other Property
Investments in Lease Equity	36,086	36,194
Other	36,201	33,488
Total Investments and Other Property	72,287	69,682
Current Assets
Cash and Cash Equivalents	28,208	25,335
Accounts Receivable—Customer	110,906	80,211
Unbilled Accounts Receivable	49,743	34,369
Allowance for Doubtful Accounts	(5,136)	(4,825)
Accounts Receivable—Due from Affiliates	3,281	6,064
Materials and Supplies	80,475	75,200
Deferred Income Taxes—Current	111,593	70,722
Fuel Inventory	39,027	44,027
Regulatory Assets—Current	66,877	42,555
Derivative Instruments	699	2,137
Other	13,923	12,923
Total Current Assets	499,596	388,718
Regulatory and Other Assets
Regulatory Assets—Noncurrent	162,872	141,030
Derivative Instruments	212	167
Other Assets	20,587	19,233
Total Regulatory and Other Assets	183,671	160,430
Total Assets	3,910,568	3,563,285
Capitalization
Common Stock Equity	1,017,778	925,923
Capital Lease Obligations	68,424	131,370
Long-Term Debt	1,372,369	1,223,070
Total Capitalization	2,458,571	2,280,363
Current Liabilities
Current Obligations Under Capital Leases	191,951	186,056
Borrowings Under Revolving Credit Facility	35,000	0
Accounts Payable—Trade	83,571	88,556
Accounts Payable—Due to Affiliates	4,099	9,153
Accrued Taxes Other than Income Taxes	53,230	34,485
Accrued Employee Expenses	18,134	24,454
Regulatory Liabilities—Current	37,125	23,701
Accrued Interest	20,043	22,785
Customer Deposits	20,370	21,354
Derivative Instruments	6,664	5,531
Other	8,420	9,244
Total Current Liabilities	478,607	425,319
Deferred Credits and Other Liabilities
Deferred Income Taxes—Noncurrent	509,062	428,103
Regulatory Liabilities—Noncurrent	302,912	263,270
Pension and Other Postretirement Benefits	79,911	84,936
Derivative Instruments	3,393	5,161
Other	78,112	76,133
Total Deferred Credits and Other Liabilities	973,390	857,603
Commitments, Contingencies & Environmental Matters (Note 5)
Total Capitalization and Other Liabilities	$ 3,910,568	$ 3,563,285