Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Current assets:
Cash and cash equivalents	$ 93,189	$ 80,517	$ 64,904
Receivables, net	1,291,949	1,305,642	948,024
Inventories	425,834	387,525	380,316
Current regulatory assets	216,318	165,092	89,078
Prepayments and other current assets	81,424	72,972	89,586
Total current assets	2,108,714	2,011,748	1,571,908
Noncurrent assets:
Property, plant and equipment	9,475,608	9,364,038	8,958,600
Less accumulated depreciation, depletion and amortization	3,322,894	3,272,493	3,158,091
Net property, plant and equipment	6,152,714	6,091,545	5,800,509
Goodwill	763,500	763,500	763,262
Other intangible assets, net	16,334	17,532	21,389
Regulatory assets	349,500	329,659	359,228
Investments	172,467	161,913	174,555
Operating lease right-of-use assets	118,052	119,375	119,845
Other	161,306	165,509	160,019
Total noncurrent assets	7,733,873	7,649,033	7,398,807
Total assets	9,842,587	9,660,781	8,970,715
Current liabilities:
Short-term borrowings	501,500	246,500	99,958
Long-term debt due within one year	78,031	78,031	147,953
Accounts payable	547,188	657,168	449,746
Taxes payable	73,914	70,810	90,572
Dividends payable	45,306	45,245	44,229
Accrued compensation	65,509	88,662	64,796
Operating lease liabilities due within one year	34,975	34,516	34,618
Regulatory liabilities due within one year	44,395	26,440	31,186
Other accrued liabilities	245,511	232,231	203,670
Total current liabilities	1,636,329	1,479,603	1,166,728
Noncurrent liabilities:
Long-term debt	2,769,037	2,763,394	2,599,810
Deferred income taxes	642,069	631,303	587,940
Asset retirement obligations	409,547	405,885	463,080
Regulatory liabilities	454,669	448,454	433,628
Operating lease liabilities	83,632	85,534	85,874
Other	271,922	259,479	272,937
Total noncurrent liabilities	4,630,876	4,594,049	4,443,269
Commitments and contingencies
Stockholders' equity:
Common stock	204,163	204,163	203,889
Other paid-in capital	1,461,294	1,466,037	1,451,464
Retained earnings	1,943,917	1,951,138	1,749,726
Accumulated other comprehensive loss	(30,366)	(30,583)	(40,735)
Treasury Stock, Common, Value	3,626	3,626	3,626
Total stockholders' equity	3,575,382	3,587,129	3,360,718
Total liabilities and stockholders' equity	$ 9,842,587	$ 9,660,781	$ 8,970,715
Common Stock, Shares Authorized	500,000,000	500,000,000	500,000,000
Common Stock, Par or Stated Value Per Share	$ 1.00	$ 1.00	$ 1.00
Common Stock, Shares, Issued	204,162,814	204,162,814	203,889,661
Treasury Stock, Common, Shares	538,921	538,921	538,921

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(8)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(14))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482099/360-10-50-1