Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 22,055	$ 16,796
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Asset impairments		115
Stock-based compensation	1,140	576
Gain on disposal of other assets	(19)	(988)
Deferred income taxes	(206)	(870)
Excess tax benefit from share-based payment arrangements	(2,937)	(749)
(Increase) decrease (net of acquisitions and dispositions):
Trade receivables, net	(960)	(11,633)
Inventories	7,890	(62,113)
Other current assets	5,757	5,292
Other non-current assets	(424)	2,778
Increase (decrease) (net of acquisitions and dispositions):
Floor plan notes payable	2,257	(3,324)
Trade payables	(410)	1,549
Accrued liabilities	6,188	5,105
Other long-term liabilities and deferred revenue	4,705	2,280
Net cash provided by (used in) operating activities	49,757	(40,987)
Cash flows from investing activities:
Principal payments received on notes receivable	319	25
Capital expenditures	(6,585)	(8,459)
Proceeds from sales of assets	440	1,009
Payments for life insurance policies	(2,641)	(1,968)
Proceeds from sales of stores		2,901
Net cash used in investing activities	(8,467)	(6,492)
Cash flows from financing activities:
Borrowings on floor plan notes payable: non-trade	953	39,401
Borrowings on lines of credit	118,000	5,000
Repayments on lines of credit	(156,303)	(12,000)
Proceeds from issuance of long-term debt		8,069
Proceeds from issuance of common stock	966	869
Repurchase of common stock	(7,903)	(2,653)
Excess tax benefit from share-based payment arrangements	2,937	749
Dividends paid		(1,814)
Net cash provided by (used in) financing activities	(69,123)	35,593
Decrease in cash and cash equivalents	(27,833)	(11,886)
Cash and cash equivalents at beginning of year	42,839	20,851
Cash and cash equivalents at end of year	15,006	8,965
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	5,837	5,794
Cash paid (refunded) during the period for income taxes, net	(964)	2,122
Supplemental schedule of non-cash activities:
Floor plan debt paid in connection with store disposals		6,712
Scheduled Payments [Member]
Cash flows from financing activities:
Principal payments on long-term debt	(2,003)	(2,028)
Other Payments [Member]
Cash flows from financing activities:
Principal payments on long-term debt	(25,770)
Segment, Continuing Operations [Member]
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	4,721	4,138
Segment, Discontinued Operations [Member]
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization		$ 61