CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents		$ 3,585	$ 7,635
Accounts receivable, net		300,882	322,885
Accounts receivable from affiliates		4,909	50,842
Investments in utility money pool arrangement		0	16,000
Accrued unbilled revenues		276,212	294,049
Inventories		205,562	238,979
Regulatory assets		92,072	120,120
Deferred income taxes		62,662	64,587
Derivative instruments		1,945	1,731
Prepaid Taxes		81,162	90,365
Prepayments and other		22,698	23,979
Total current assets		1,051,689	1,231,172
Property, plant and equipment, net		12,172,211	11,626,956
Other assets
Regulatory assets		906,275	903,973
Derivative instruments		3,478	5,176
Other		44,819	48,506
Total other assets		954,572	957,655
Total assets		14,178,472	13,815,783
Current liabilities
Current portion of long-term debt		8,103	8,178
Short-term debt		14,000	382,000
Accounts payable		352,701	425,133
Accounts payable to affiliates		76,643	46,736
Regulatory liabilities	[1]	152,823	134,459
Taxes accrued		166,660	159,470
Accrued interest		49,698	48,409
Dividends payable to parent		83,374	83,652
Derivative instruments		8,881	5,774
Other		78,910	72,002
Total current liabilities		991,793	1,365,813
Deferred credits and other liabilities
Deferred income taxes		2,720,860	2,437,641
Deferred investment tax credits		33,466	36,273
Regulatory liabilities		471,421	464,421
Asset retirement obligations		240,508	225,296
Derivative instruments		13,020	18,257
Customer advances		198,526	229,990
Pension and employee benefit obligations		200,774	202,031
Other		63,864	68,171
Total deferred credits and other liabilities		$ 3,942,439	$ 3,682,080
Commitments and contingencies
Capitalization
Long-term debt		$ 4,124,088	$ 3,882,051
Common stock — 100 shares authorized of $0.01 par value; 100 shares outstanding at Dec. 31, 2015 and 2014, respectively		0	0
Additional paid in capital		3,620,824	3,522,788
Retained earnings		1,523,164	1,386,929
Accumulated other comprehensive loss		(23,836)	(23,878)
Total common stockholder’s equity		5,120,152	4,885,839
Total liabilities and equity		$ 14,178,472	$ 13,815,783

[1] Revenue subject to refund of $9.1 million and $4.4 million for 2015 and 2014, respectively, is included in other current liabilities.