CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 6,285	$ 5,926
Accounts receivable, net	301,413	304,900
Accounts receivable from affiliates	12,189	9,421
Accrued unbilled revenues	205,978	297,078
Inventories	161,723	202,220
Regulatory assets	85,609	103,783
Derivative instruments	5,416	10,934
Prepayments and other	33,900	34,559
Total current assets	812,513	968,821
Property, plant and equipment, net	13,013,418	12,849,799
Other assets
Regulatory assets	959,308	958,429
Derivative instruments	1,317	3,398
Other	25,042	25,637
Total other assets	985,667	987,464
Total assets	14,811,598	14,806,084
Current liabilities
Current portion of long-term debt	5,263	5,270
Short-term debt	31,000	129,000
Accounts payable	310,260	376,186
Accounts payable to affiliates	45,201	98,797
Regulatory liabilities	90,896	101,110
Taxes accrued	215,408	171,862
Accrued interest	29,947	48,619
Dividends payable to parent	87,104	74,208
Derivative instruments	6,005	6,788
Other	64,648	73,022
Total current liabilities	885,732	1,084,862
Deferred credits and other liabilities
Deferred income taxes	2,953,865	2,889,129
Deferred investment tax credits	29,960	30,661
Regulatory liabilities	521,785	512,933
Asset retirement obligations	292,589	289,563
Derivative instruments	6,538	7,828
Pension and employee benefit obligations	269,345	285,774
Other	222,204	224,943
Total deferred credits and other liabilities	4,296,286	4,240,831
Commitments and contingencies
Capitalization
Long-term debt	4,210,435	4,210,936
Common stock — 100 shares authorized at $0.01 par value; 100 shares outstanding at March 31, 2017 and Dec. 31, 2016, respectively	0	0
Additional paid in capital	3,758,217	3,633,216
Retained earnings	1,683,681	1,659,239
Accumulated other comprehensive loss	(22,753)	(23,000)
Total common stockholders’ equity	5,419,145	5,269,455
Total liabilities and equity	$ 14,811,598	$ 14,806,084