Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating activities
Net margins including noncontrolling interest	$ 70,524	$ 38,122
Adjustments to reconcile net margins to net cash used in operating activities:
Depreciation, amortization, and depletion	131,094	126,090
Amortization of intangible asset	5,493	5,493
Amortization of NRECA Retirement Security Plan prepayment	4,029	4,029
Amortization of debt issuance costs	1,479	1,436
Impairment loss - Holcomb Expansion	93,494
Deferred Holcomb Expansion impairment loss	(93,494)
Deferred membership withdrawal income		47,572
Recognition of deferred membership withdrawal income	(5,000)
Capital credit allocations from cooperatives and income from coal mines over refund distributions	(1,892)	(2,546)
Recognition of deferred revenue	(15,000)
Change in restricted cash and investments	(126)	(121)
Changes in operating assets and liabilities:
Accounts receivable	(5,754)	(865)
Coal inventory	15,689	733
Materials and supplies	(177)	(3,402)
Accounts payable and accrued expenses	(7,973)	(4,360)
Accrued interest	16,494	17,582
Accrued property taxes	(2,467)	(744)
Other deferred credits - TEP transmission settlement	(15,521)
Other deferred credits - TEP transmission refund		2,313
Other	(11,580)	(4,784)
Net cash provided by operating activities	179,312	226,548
Investing activities
Purchases of plant	(159,656)	(150,336)
Changes in deferred charges	(239)	(7,390)
Proceeds from other investments	61	313
Net cash used in investing activities	(159,834)	(157,413)
Financing activities
Changes in Member advances	(4,590)	(980)
Payments of long-term debt	(103,138)	(416,532)
Proceeds from issuance of debt		307,000
Increase in short-term borrowings, net	55,181	74,951
Proceeds from investment in securities pledged as collateral		4,647
Retirement of patronage capital	(3,023)	(15,345)
Other	(163)	(231)
Net cash used in financing activities	(55,733)	(46,490)
Net increase (decrease) in cash and cash equivalents	(36,255)	22,645
Cash and cash equivalents - beginning	165,893	144,587
Cash and cash equivalents - end	129,638	167,232
Supplemental cash flow information:
Cash paid for interest	101,965	101,066
Cash paid for income taxes		700
Supplemental disclosure of noncash investing and financing activities:
Change in plant expenditures included in accounts payable	$ (3,287)	$ (4,974)