BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 10,871	$ 844
Accounts receivable, net	79,581	74,190
Accounts receivable from affiliates	1,297	949
Investments in money pool arrangements	65,000	0
Accrued unbilled revenues	129,804	119,418
Inventories	40,433	38,505
Regulatory assets	31,538	38,721
Derivative instruments	15,882	5,114
Prepaid taxes	15,025	21,779
Prepayments and other	10,341	7,855
Total current assets	399,772	307,375
Property, plant and equipment, net	5,095,609	4,695,819
Other assets
Regulatory assets	362,943	346,683
Derivative instruments	18,954	22,113
Other	11,266	7,477
Total other assets	393,163	376,273
Total assets	5,888,544	5,379,467
Current liabilities
Short-term debt	0	50,000
Accounts payable	211,756	176,157
Accounts payable to affiliates	22,577	14,414
Regulatory liabilities	68,835	41,577
Taxes accrued	35,243	39,742
Accrued interest	23,275	19,162
Dividends payable	26,753	30,870
Derivative instruments	3,565	3,565
Other	29,641	29,703
Total current liabilities	421,645	405,190
Deferred credits and other liabilities
Deferred income taxes	574,906	989,137
Regulatory liabilities	784,564	233,454
Asset retirement obligations	28,524	28,663
Derivative instruments	19,949	23,513
Pension and employee benefit obligations	90,266	107,872
Other	8,386	24,084
Total deferred credits and other liabilities	1,506,595	1,406,723
Commitments and contingencies
Capitalization
Long-term debt	1,829,941	1,635,858
Common stock — 200 shares authorized of $1.00 par value; 100 shares outstanding at Dec. 31, 2017 and 2016, respectively	0	0
Additional paid in capital	1,590,242	1,446,223
Retained earnings	541,588	486,763
Accumulated other comprehensive loss	(1,467)	(1,290)
Total common stockholder’s equity	2,130,363	1,931,696
Total liabilities and equity	$ 5,888,544	$ 5,379,467