Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 82,124,000	$ 48,165,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	23,630,000	20,678,000
Deferred income taxes	8,100,000	8,910,000
Asset Impairment Charges	1,039,000	1,721,000
Stock-based compensation	9,453,000	7,886,000
Amortization of debt discount and issue costs	1,812,000	7,235,000
Loss on extinguishment of 3.00% Convertible Notes	0	23,614,000
Gain (Loss) on Disposition of Assets	1,507,000	649,000
Tax effect from excess stock-based compensation	(1,439,000)	(1,103,000)
Other	2,278,000	1,146,000
Changes in operating assets and liabilities, net of effects of acquisitions and dispositions:
Accounts payable and accrued expenses	31,197,000	30,383,000
Accounts and notes receivable	1,399,000	(4,825,000)
Inventories	(88,738,000)	24,403,000
Contracts-in-transit and vehicle receivables	3,243,000	14,964,000
Prepaid expenses and other assets	3,427,000	658,000
IncreaseDecreaseFloorPlanNotes	4,876,000	(52,458,000)
Deferred revenues	(319,000)	205,000
Net cash provided by (used in) operating activities	80,575,000	130,933,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Cash paid in acquisitions, net of cash received	(130,783,000)	(129,276,000)
Proceeds from disposition of franchises, property and equipment	7,339,000	9,764,000
Purchases of property and equipment, including real estate	(48,486,000)	(68,726,000)
Other	6,294,000	(6,125,000)
Net cash provided by (used in) investing activities	(165,636,000)	(194,363,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings on credit facility - Floorplan Line	3,550,526,000	3,735,607,000
Repayments on credit facility - Floorplan Line	(3,466,772,000)	(3,762,092,000)
Borrowings on Credit Facility - Acquisition Line	346,050,000	89,963,000
Repayments on Credit Facility - Acquisition Line	(324,222,000)	(130,000,000)
Borrowings on real estate credit facility	0	200,000
Principal payments on real estate credit facility	(1,670,000)	(1,603,000)
Proceeds from Issuance of Unsecured Debt	0	344,750,000
Payments of Debt Issuance Costs	0	1,221,000
Repayments of 3.00% Convertible Notes	0	210,356,000
Borrowings of other long-term debt	25,744,000	53,038,000
Principal payments of other long-term debt	(26,942,000)	(47,167,000)
Borrowings of long term debt related to real estate loans	22,430,000	32,559,000
Principal payments of long-term debt related to real estate loans	(12,689,000)	(16,236,000)
Stock Issued During Period, Shares, Employee Stock Purchase Plans	(1,113,000)	55,000
Repurchases of common stock, amounts based on settlement date	(33,121,000)	(16,942,000)
Tax effect from excess stock-based compensation	1,439,000	1,103,000
Dividends paid	(9,737,000)	(8,235,000)
Net cash provided by (used in) financing activities	69,923,000	63,423,000
Effect of Exchange Rate on Cash and Cash Equivalents	(1,612,000)	1,087,000
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(16,750,000)	1,080,000
CASH AND CASH EQUIVALENTS, beginning of period	40,975,000	20,215,000
CASH AND CASH EQUIVALENTS, end of period	24,225,000	21,295,000
SUPPLEMENTAL CASH FLOW INFORMATION:
Purchases of property and equipment, including real estate, accrued in accounts payable and accrued expenses	$ 5,731,000	$ 656,000