Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Current assets:
Cash and cash equivalents	$ 116,526	$ 66,459	$ 49,721
Receivables, net	835,468	836,605	722,152
Inventories	305,958	278,407	311,535
Current regulatory assets	55,206	63,613	74,494
Prepayments and other current assets	60,230	52,617	77,327
Total current assets	1,373,388	1,297,701	1,235,229
Noncurrent assets:
Property, plant and equipment	8,008,338	7,908,628	7,502,368
Less accumulated depreciation, depletion and amortization	3,039,812	2,991,486	2,858,986
Net property, plant and equipment	4,968,526	4,917,142	4,643,382
Goodwill	713,527	681,358	679,395
Other intangible assets, net	34,250	15,246	11,680
Regulatory assets	348,189	353,784	319,119
Investments	145,237	148,656	144,616
Operating lease right-of-use assets	114,382	115,323	107,486
Other	153,017	153,849	138,016
Total noncurrent assets	6,477,128	6,385,358	6,043,694
Total assets	7,850,516	7,683,059	7,278,923
Current liabilities:
Short-term borrowings	0	0	70,000
Long-term debt due within one year	16,560	16,540	251,846
Accounts payable	384,339	403,391	352,180
Taxes payable	58,743	48,970	55,319
Dividends payable	41,608	41,580	39,875
Accrued compensation	55,199	99,269	45,383
Regulatory liabilities due within one year	60,072	42,935	61,390
Operating lease liabilities due within one year	31,141	31,664	30,978
Asset retirement obligations due within one year	4,256	4,277	4,994
Other accrued liabilities	172,561	177,801	150,814
Total current liabilities	824,479	866,427	1,062,779
Noncurrent liabilities:
Long-term debt	2,438,675	2,226,567	1,946,181
Deferred income taxes	515,711	506,583	444,965
Regulatory liabilities	443,205	447,370	457,084
Asset retirement obligations	417,469	413,298	375,827
Operating lease liabilities	83,414	83,742	76,444
Other	290,971	291,826	309,951
Total noncurrent liabilities	4,189,445	3,969,386	3,610,452
Commitments and contingencies
Stockholders' equity:
Common stock Authorized - 500,000,000 shares, $1.00 par value Shares issued - 201,061,198 at March 31, 2020, 198,316,808 at March 31, 2019 and 200,922,790 at December 31, 2019	201,061	200,923	198,317
Other paid-in capital	1,360,564	1,355,404	1,284,060
Retained earnings	1,319,988	1,336,647	1,164,509
Accumulated other comprehensive loss	(41,395)	(42,102)	(37,568)
Treasury stock at cost - 538,921 shares	(3,626)	(3,626)	(3,626)
Total stockholders' equity	2,836,592	2,847,246	2,605,692
Total liabilities and stockholders' equity	$ 7,850,516	$ 7,683,059	$ 7,278,923