Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net income	$ 31,852	$ 19,179
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	59,298	44,228
Gain on sale of property and equipment	(104)	(29)
Stock-based compensation expense related to stock options and employee stock purchases	7,078	5,515
Provision for deferred income tax	(2,802)	(924)
Excess tax benefits from stock-based compensation	(4,306)	(2,138)
Acquired research and development	2,000
Change in accounts receivable, net	(55,700)	404
Change in inventories, net	(10,095)	(44,330)
Change in prepaid expenses and other, net	4,694	5,209
Change in trade accounts payable	5,766	19,552
Draws on floor plan notes payable – trade, net	19,903	4,789
Change in customer deposits	(26,130)	(6,020)
Change in accrued expenses	15,161	(8,705)
Net cash provided by operating activities	46,615	36,730
Cash flows from investing activities:
Acquisition of property and equipment	(116,204)	(82,532)
Proceeds from the sale of property and equipment	299	332
Business acquisitions	(147,269)	(3,528)
Proceeds from the sale of available for sale securities	150
Change in other assets	1,733	(66)
Net cash used in investing activities	(261,291)	(85,794)
Cash flows from financing activities:
Draws on floor plan notes payable – non-trade, net	73,344	33,002
Proceeds from long-term debt	114,210	65,651
Principal payments on long-term debt	(56,897)	(45,585)
Principal payments on capital lease obligations	(7,187)	(6,446)
Proceeds from issuance of shares relating to employee stock options and employee stock purchases	9,256	7,337
Excess tax benefits from stock-based compensation	4,306	2,138
Common stock repurchased	(8,698)	(2,272)
Net cash provided by financing activities	128,334	53,825
Net (decrease) increase in cash and cash equivalents	(86,342)	4,761
Cash and cash equivalents, beginning of period	217,305	198,773
Cash and cash equivalents, end of period	130,963	203,534
Cash paid during the period for:
Interest	14,460	11,334
Income taxes, net of refunds	5,425	1,360
Noncash investing activities:
Common stock issued related to business acquisition	2,000
Assets acquired under capital leases	$ 6,415	$ 4,124