CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents		$ 5,926	$ 3,585
Accounts receivable, net		304,900	300,882
Accounts receivable from affiliates		9,421	4,909
Accrued unbilled revenues		297,078	276,212
Inventories		202,220	205,562
Regulatory assets		103,783	92,072
Derivative instruments		10,934	1,945
Prepaid Taxes		9,124	81,162
Prepayments and other		25,435	22,698
Total current assets		968,821	989,027
Property, plant and equipment, net		12,849,799	12,172,211
Other assets
Regulatory assets		958,429	906,275
Derivative instruments		3,398	3,478
Other		25,637	18,224
Total other assets		987,464	927,977
Total assets		14,806,084	14,089,215
Current liabilities
Current portion of long-term debt		5,270	8,103
Short-term debt		129,000	14,000
Accounts payable		376,186	352,701
Accounts payable to affiliates		98,797	76,643
Regulatory liabilities	[1]	101,110	152,823
Taxes accrued		171,862	166,660
Accrued interest		48,619	49,698
Dividends payable to parent		74,208	83,374
Derivative instruments		6,788	8,881
Other		73,022	78,910
Total current liabilities		1,084,862	991,793
Deferred credits and other liabilities
Deferred income taxes		2,889,129	2,658,198
Deferred investment tax credits		30,661	33,466
Regulatory liabilities		512,933	471,421
Asset retirement obligations		289,563	240,508
Derivative instruments		7,828	13,020
Customer advances		162,742	198,526
Pension and employee benefit obligations		285,774	200,774
Other		62,201	63,864
Total deferred credits and other liabilities		4,240,831	3,879,777
Commitments and contingencies
Capitalization
Long-term debt		4,210,936	4,097,493
Common stock — 100 shares authorized of $0.01 par value; 100 shares outstanding at Dec. 31, 2016 and 2015, respectively		0	0
Additional paid in capital		3,633,216	3,620,824
Retained earnings		1,659,239	1,523,164
Accumulated other comprehensive loss		(23,000)	(23,836)
Total common stockholder’s equity		5,269,455	5,120,152
Total liabilities and equity		$ 14,806,084	$ 14,089,215

[1] (b) Revenue subject to refund of $2.4 million and $9.1 million for 2016 and 2015, respectively, is included in other current liabilities.