Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Activities:
Net income	$ 48,424	$ 115,881
Non-cash items included in net income:
Depreciation and amortization	51,421	49,123
Provision for deferred income taxes	(6,765)	8,883
Power and natural gas cost amortizations (deferrals), net	6,380	(48,084)
Amortization of debt expense	653	669
Amortization of investment in exchange power	0	613
Stock-based compensation expense	872	4,845
Equity-related AFUDC	(1,599)	(1,485)
Pension and other postretirement benefit expense	7,952	9,084
Other regulatory assets and liabilities and deferred debits and credits	11,902	1,016
Change in decoupling regulatory deferral	4,155	4,471
Gain on sale of investments	(3,242)	0
Other	5,112	(1,943)
Contributions to defined benefit pension plan	(7,300)	(7,300)
Changes in certain current assets and liabilities:
Accounts and notes receivable	6,078	(9,787)
Materials and supplies, fuel stock and natural gas stored	9,901	(394)
Collateral posted for derivative instruments	(14,283)	3,432
Income taxes receivable	10,500	0
Income taxes payable	4,901	19,360
Other current assets	(2,166)	1,705
Accounts payable	(19,527)	16,697
Other current liabilities	21,905	30,095
Net cash provided by operating activities	135,274	196,881
Investing Activities:
Utility property capital expenditures (excluding equity-related AFUDC)	(95,525)	(93,615)
Issuance of notes receivable by subsidiaries	(2,779)	(200)
Equity and property investments made by subsidiaries	(1,313)	(3,504)
Proceeds from sale of investments made by subsidiaries	5,148	0
Other	(662)	(345)
Net cash used in investing activities	(95,131)	(97,664)
Financing Activities:
Net decrease in short-term borrowings	(800)	(71,000)
Maturity of long-term debt and finance leases	(700)	(665)
Issuance of common stock	175	190
Cash dividends paid	(27,389)	(25,615)
Other	(2,406)	(896)
Net cash used in financing activities	(31,120)	(97,986)
Net increase in cash and cash equivalents	9,023	1,231
Cash and cash equivalents at beginning of period	9,896	14,656
Cash and cash equivalents at end of period	$ 18,919	$ 14,861