Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 92,093	$ 66,262
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	142,648	117,054
Gain on sale of property and equipment	(159)	(76)
Stock-based compensation expense related to stock options and employee stock purchases	15,850	12,036
Deferred income tax expense	12,125	8,609
Change in accounts receivable, net	6,172	(1,481)
Change in inventories, net	(200,662)	(87,799)
Change in prepaid expenses and other, net	1,241	1,156
Change in trade accounts payable	26,238	12,469
Draws on floor plan notes payable – trade, net	87,548	26,439
Change in customer deposits	13,219	4,558
Change in accrued expenses	6,710	11,048
Net cash provided by operating activities	203,023	170,275
Cash flows from investing activities:
Acquisition of property and equipment	(176,221)	(138,756)
Proceeds from the sale of property and equipment	5,822	3,905
Proceeds from the sale of available for sale securities	6,375	325
Change in other assets	(1,803)	4,831
Net cash used in investing activities	(165,827)	(129,695)
Cash flows from financing activities:
Draws on floor plan notes payable – non-trade, net	124,485	33,611
Proceeds from long-term debt	115,216	97,319
Principal payments on long-term debt	(127,354)	(108,526)
Principal payments on capital lease obligations	(9,511)	(9,280)
Proceeds from issuance of shares relating to employee stock options and employee stock purchases	3,764	20,096
Payments of cash dividends	(4,692)
Common stock repurchased	(58,076)	(27,388)
Debt issuance costs		(523)
Net cash provided by financing activities	43,832	5,309
Net increase in cash and cash equivalents	81,028	45,889
Cash and cash equivalents, beginning of period	124,541	82,026
Cash and cash equivalents, end of period	205,569	127,915
Supplemental disclosure of cash flow information:
Interest	31,002	24,952
Income taxes, net of refunds	15,990	30,487
Assets acquired under capital leases	$ 3,241	$ 8,243