Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating Activities:
Net income	$ 145,987	$ 90,729
Non-cash items included in net income:
Depreciation and amortization	154,943	139,738
Provision for deferred income taxes	10,219	10,575
Power and natural gas cost amortizations (deferrals), net	(45,835)	6,315
Amortization of debt expense	2,008	2,327
Amortization of investment in exchange power	1,633	1,838
Stock-based compensation expense	8,951	5,215
Equity-related AFUDC	(5,021)	(4,406)
Pension and other postretirement benefit expense	27,139	23,980
Other regulatory assets and liabilities and deferred debits and credits	1,871	20,953
Change in decoupling regulatory deferral	(11,540)	5,436
Gain on sale of METALfx (before payment of transaction costs)	(6,477)	0
Other	(5,095)	3,962
Contributions to defined benefit pension plan	(22,000)	(22,000)
Cash paid for settlement of interest rate swap agreements	(13,325)	(32,174)
Cash received for settlement of interest rate swap agreements	0	5,594
Changes in certain current assets and liabilities:
Accounts and notes receivable (billed and unbilled)	54,554	75,878
Materials and supplies, fuel stock and natural gas stored	(7,298)	(4,691)
Collateral posted for derivative instruments	64,770	47,150
Other current assets	(11,423)	(3,871)
Accounts payable	(8,366)	(16,392)
Other current liabilities	4,796	9,639
Net cash provided by operating activities	340,491	365,795
Investing Activities:
Utility property capital expenditures (excluding equity-related AFUDC)	(320,964)	(296,216)
Issuance of notes receivable by subsidiaries	(6,036)	(2,930)
Equity and property investments made by subsidiaries	(10,031)	(8,629)
Proceeds from sale of METALfx (net of cash sold)	16,407	0
Other	309	88
Net cash used in investing activities	(320,315)	(307,687)
Financing Activities:
Net increase (decrease) in short-term borrowings	17,000	(70,398)
Proceeds from issuance of long-term debt	0	374,621
Maturity of long-term debt and capital leases	(1,995)	(276,804)
Issuance of common stock	42,899	1,224
Cash dividends paid	(76,772)	(73,569)
Other	(1,510)	(8,184)
Net cash used in financing activities	(20,378)	(53,110)
Net increase (decrease) in cash and cash equivalents	(202)	4,998
Cash and cash equivalents at beginning of period	14,656	16,172
Cash and cash equivalents at end of period	$ 14,454	$ 21,170