Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating Activities:
Net income	$ 140,897	$ 80,600
Non-cash items included in net income:
Depreciation and amortization	104,757	92,584
Provision for deferred income taxes	5,577	(1,272)
Power and natural gas cost amortizations (deferrals), net	(47,716)	6,701
Amortization of debt expense	1,338	1,635
Amortization of investment in exchange power	1,225	1,225
Stock-based compensation expense	7,009	3,878
Equity-related AFUDC	(3,253)	(2,845)
Pension and other postretirement benefit expense	18,040	16,025
Other regulatory assets and liabilities and deferred debits and credits	1,122	21,323
Change in decoupling regulatory deferral	(5,444)	2,226
Gain on sale of METALfx (before payment of transaction costs)	(6,477)	0
Other	(3,904)	2,108
Contributions to defined benefit pension plan	(14,600)	(14,600)
Cash paid for settlement of interest rate swap agreements	0	(31,484)
Cash received for settlement of interest rate swap agreements	0	5,594
Changes in certain current assets and liabilities:
Accounts and notes receivable	47,771	65,843
Materials and supplies, fuel stock and natural gas stored	(7,225)	1,174
Collateral posted for derivative instruments	47,352	44,080
Other current assets	(8,783)	3,832
Accounts payable	(19,393)	(21,642)
Other current liabilities	(5,622)	(1,560)
Net cash provided by operating activities	252,671	275,425
Investing Activities:
Utility property capital expenditures (excluding equity-related AFUDC)	(199,988)	(183,132)
Issuance of notes receivable at subsidiaries	(900)	(2,780)
Equity and property investments made by subsidiaries	(6,624)	(7,431)
Proceeds from sale of METALfx (net of cash sold)	16,407	0
Other	1,072	438
Net cash used in investing activities	(190,033)	(192,905)
Financing Activities:
Net decrease in short-term borrowings	(21,000)	(105,398)
Proceeds from issuance of long-term debt	0	374,621
Maturity of long-term debt and capital leases	(1,330)	(276,170)
Issuance of common stock	14,929	1,227
Cash dividends paid	(51,153)	(49,101)
Other	(1,509)	(8,538)
Net cash used in financing activities	(60,063)	(63,359)
Net increase in cash and cash equivalents	2,575	19,161
Cash and cash equivalents at beginning of period	14,656	16,172
Cash and cash equivalents at end of period	$ 17,231	$ 35,333