Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net Income	$ 40,539	$ 43,039
Adjustments to reconcile net income to cash provided by operations:
Depreciation and amortization	42,022	40,177
Regulatory amortization of gas reserves	7,816	8,031
Deferred income taxes	11,227	22,170
Qualified defined benefit pension plan expense	2,876	2,615
Contributions to qualified defined benefit pension plans	(5,570)	(7,250)
Deferred environmental expenditures, net	(7,330)	(6,817)
Amortization of environmental remediation	6,506	9,565
Regulatory revenue deferral from the TCJA	9,212	0
Other	810	1,128
Changes in assets and liabilities:
Receivables, net	79,332	85,250
Inventories	4,803	(3,501)
Income taxes	(11,967)	(5,243)
Accounts payable	(26,613)	(21,849)
Interest accrued	(121)	0
Deferred gas costs	4,787	15,325
Other, net	3,623	8,243
Discontinued operations	700	3,348
Cash provided by operating activities	162,652	194,231
Investing activities:
Capital expenditures	(102,370)	(94,333)
Other	195	(404)
Discontinued operations	(283)	15
Cash used in investing activities	(102,458)	(94,722)
Financing activities:
Repurchases related to stock-based compensation	0	(2,034)
Proceeds from stock options exercised	45	1,309
Long-term debt retired	22,000	0
Change in short-term debt	(7,100)	(53,300)
Cash dividend payments on common stock	(25,577)	(26,919)
Other	(279)	(1,232)
Cash used in financing activities	(54,911)	(82,176)
Increase in cash and cash equivalents	5,283	17,333
Cash and cash equivalents, beginning of period	3,472	3,521
Cash and cash equivalents, end of period	8,755	20,854
Supplemental disclosure of cash flow information:
Interest paid, net of capitalization	17,117	18,011
Income taxes paid	$ 13,347	$ 9,081