Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Utility plant:
Land	$ 44,019	$ 42,517
Depreciable plant and equipment	2,950,424	2,729,757
Construction work in progress	210,260	175,693
Intangible assets	24,743	22,212
Total utility plant	3,229,446	2,970,179
Less accumulated depreciation and amortization	(996,723)	(922,214)
Net utility plant	2,232,723	2,047,965
Current assets:
Cash and cash equivalents	47,176	94,776
Receivables: net of allowance for doubtful accounts of $757 and $773 in 2018 and 2017, respectively
Customers	30,037	32,451
Regulatory balancing accounts	42,394	36,783
Other	17,101	16,464
Unbilled revenue	33,427	29,756
Materials and supplies at weighted average cost	6,586	6,463
Taxes, prepaid expenses, and other assets	11,981	11,180
Total current assets	188,702	227,873
Other assets:
Regulatory assets	353,569	405,482
Goodwill	2,615	2,615
Other	60,095	60,775
Total other assets	416,279	468,872
TOTAL ASSETS	2,837,704	2,744,710
Capitalization:
Common stock, $0.01 par value; 68,000 shares authorized, 48,065 and 48,012 outstanding in 2018 and 2017, respectively	481	480
Additional paid-in capital	337,623	336,229
Retained earnings	392,053	362,512
Total common stockholders' equity	730,157	699,221
Long-term debt, net	710,027	515,793
Total capitalization	1,440,184	1,215,014
Current liabilities:
Current maturities of long-term debt, net	104,911	15,920
Short-term borrowings	65,100	275,100
Accounts payable	95,580	93,955
Regulatory balancing accounts	12,213	59,303
Accrued other taxes	4,182	3,888
Accrued interest	5,674	6,122
Other accrued liabilities	33,506	36,671
Total current liabilities	321,166	490,959
Unamortized investment tax credits	1,649	1,724
Deferred income taxes	213,033	194,617
Regulatory liabilities	211,275	176,611
Pension and postretirement benefits other than pensions	193,538	252,141
Advances for construction	186,342	182,502
Contributions in aid of construction	225,270	186,721
Other long-term liabilities	45,247	44,421
Commitments and contingencies
TOTAL CAPITALIZATION AND LIABILITIES	$ 2,837,704	$ 2,744,710