Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net income	$ 17,496	$ 15,470
Adjustments to reconcile net income (loss) to net cash from operating activities:
Accretion of asset retirement obligations	256	247
Depreciation and amortization	8,938	5,393
Amortization of debt issuance costs	28	187
Equity-based compensation.	1,954	1,245
Deferred income tax expense	3,429	1,385
Changes in operating assets and liabilities
Accounts receivable	(15,370)	(21,100)
Prepaid expenses	1,550	(977)
Inventories	(2,408)	(1,237)
Advance coal royalties	(68)	82
Other assets	135	(206)
Accounts payable	(4,121)	1,340
Accrued expenses	1,295	6,282
Net cash from operating activities	13,114	8,111
Cash flow from investing activities
Purchases of property, plant and equipment	(19,737)	(27,478)
Proceeds from maturities of investment securities		5,200
Net cash from investing activities	(19,737)	(22,278)
Cash flows from financing activities
Proceeds from borrowings	44,300	13,000
Proceeds from notes payable - related party		3,000
Payment of debt issuance costs		(429)
Repayments of borrowings	(38,800)	(1,000)
Repayments of financed insurance payable	(287)	(427)
Net cash from financing activities	5,213	14,144
Net change in cash and cash equivalents	(1,410)	(23)
Cash and cash equivalents, beginning of period	6,951	5,934
Cash and cash equivalents, end of period	5,541	5,911
Supplemental cash flow information
Cash paid for interest	568	340
Non-cash investing and financing activities
Capital expenditures included in accounts payable and accrued liabilities	5,373	2,128
Financed insurance		789
Additional asset retirement obligations acquired or incurred	$ 137	$ 127