Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities
Net margins including noncontrolling interest	$ 8,891	$ 23,822
Adjustments to reconcile net margins to net cash provided by operating activities:
Depreciation, amortization, and depletion	40,088	46,672
Amortization of intangible asset	1,831	1,831
Amortization of NRECA Retirement Security Plan prepayment	1,343	1,343
Amortization of debt issuance costs	514	527
Recognition of deferred membership withdrawal income		(2,500)
Recognition of deferred revenue		(7,500)
Capital credit allocations from cooperatives and income from coal mines over refund distributions	(1,105)	(1,199)
Changes in operating assets and liabilities:
Accounts receivable	677	4,195
Coal inventory	(15,954)	3,394
Materials and supplies	(826)	1,439
Accounts payable and accrued expenses	(14,708)	(10,732)
Accrued interest	1,902	16,775
Accrued property taxes	(891)	(1,053)
Other deferred credits - TEP transmission settlement		(15,521)
Other	(7,782)	(12,656)
Net cash provided by operating activities	13,980	48,837
Investing activities
Purchases of plant	(56,999)	(32,628)
Changes in deferred charges	1,003	1,707
Proceeds from other investments	64	61
Net cash used in investing activities	(55,932)	(30,860)
Financing activities
Changes in Member advances	(4,230)	(5,611)
Payments of long-term debt	(17,738)	(48,502)
Increase in short-term borrowings, net	44,668	5,580
Retirement of patronage capital	(4,852)	(3,023)
Equity distribution to noncontrolling interest	(2,858)
Other	(12)	304
Net cash provided by (used in) financing activities	14,978	(51,252)
Net increase (decrease) in cash, cash equivalents and restricted cash and investments	(26,974)	(33,275)
Cash, cash equivalents and restricted cash and investments – beginning	150,965	167,890
Cash, cash equivalents and restricted cash and investments – ending	123,991	134,615
Supplemental cash flow information:
Cash paid for interest	37,963	23,016
Supplemental disclosure of noncash investing and financing activities:
Change in plant expenditures included in accounts payable	$ (739)	$ (3,916)