CONSOLIDATED BALANCE SHEETS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 664	$ 1,349
Accounts receivable, net	51,684	57,674
Accounts receivable from affiliates	5,480	1,595
Accrued unbilled revenues	41,174	51,634
Inventories	18,803	21,475
Regulatory assets	24,835	14,866
Prepaid taxes	24,278	27,518
Deferred income taxes	10,975	14,953
Prepayments and other	4,356	5,056
Total current assets	182,249	196,120
Property, plant and equipment, net	1,521,829	1,442,779
Other assets
Regulatory assets	252,169	233,193
Other investments	3,643	3,650
Other	4,164	3,651
Total other assets	259,976	240,494
Total assets	1,964,054	1,879,393
Current liabilities
Current portion of long-term debt	1,207	107
Short-term debt	11,000	68,000
Notes payable to affiliates	500	470
Accounts payable	34,353	52,086
Accounts payable to affiliates	28,360	24,986
Dividends payable to parent	16,243	8,032
Regulatory liabilities	4,047	9,717
Taxes accrued	5,539	5,638
Environmental liabilities	34,380	28,785
Accrued interest	7,593	7,507
Other	8,341	9,376
Total current liabilities	151,563	214,704
Deferred credits and other liabilities
Deferred income taxes	320,334	305,139
Deferred investment tax credits	9,361	9,698
Regulatory liabilities	134,492	126,424
Environmental liabilities	80,109	79,703
Customer advances	16,678	16,008
Pension and employee benefit obligations	38,330	45,708
Other	9,362	9,237
Total deferred credits and other liabilities	608,666	591,917
Commitments and contingencies
Capitalization
Long-term debt	567,070	468,490
Common stock — 1,000,000 shares authorized of $100 par value; 933,000 shares outstanding at June 30, 2014 and Dec. 31, 2013, respectively	93,300	93,300
Additional paid in capital	269,322	248,844
Retained earnings	274,457	262,499
Accumulated other comprehensive loss	(324)	(361)
Total common stockholder’s equity	636,755	604,282
Total liabilities and equity	$ 1,964,054	$ 1,879,393