Condensed Consolidated Financial Information Condensed Consolidated Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Condensed Income Statements, Captions [Line Items]
REVENUES:	$ 2,800,569	$ 2,626,448	$ 7,959,903	$ 7,398,949
COST OF SALES:	2,402,187	2,251,739	6,806,064	6,316,970
GROSS PROFIT	398,382	374,709	1,153,839	1,081,979
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	289,012	264,233	841,050	793,761
DEPRECIATION AND AMORTIZATION EXPENSE	11,811	10,746	35,441	31,424
ASSET IMPAIRMENTS	916	9,373	1,955	11,094
INCOME FROM OPERATIONS	96,643	90,357	275,393	245,700
Floorplan interest expense	(9,685)	(10,452)	(29,046)	(31,695)
Interest Expense, Other	(13,922)	(13,246)	(42,061)	(36,326)
Loss on extinguishment of long-term debt	0	(22,790)	0	(46,403)
INCOME BEFORE INCOME TAXES	73,036	43,869	204,286	131,276
BENEFIT (PROVISION) FOR INCOME TAXES	(27,775)	(17,707)	(76,901)	(56,949)
EQUITY IN EARNINGS OF SUBSIDIARIES	0	0	0	0
NET INCOME	45,261	26,162	127,385	74,327
COMPREHENSIVE LOSS	(42,465)	(19,572)	(63,821)	(7,823)
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO PARENT	2,796	6,590	63,564	66,504
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
REVENUES:	0	0	0	0
COST OF SALES:	0	0	0	0
GROSS PROFIT	0	0	0	0
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	555	559	2,612	2,315
DEPRECIATION AND AMORTIZATION EXPENSE	0	0	0	0
ASSET IMPAIRMENTS	0	0	0	0
INCOME FROM OPERATIONS	(555)	(559)	(2,612)	(2,315)
Floorplan interest expense	0	0	0	0
Interest Expense, Other	648	567	1,845	1,696
Loss on extinguishment of long-term debt		0		0
INCOME BEFORE INCOME TAXES	93	8	(767)	(619)
BENEFIT (PROVISION) FOR INCOME TAXES	(35)	(3)	288	232
EQUITY IN EARNINGS OF SUBSIDIARIES	45,203	26,157	127,864	74,714
NET INCOME	45,261	26,162	127,385	74,327
COMPREHENSIVE LOSS	0	0	0	0
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO PARENT	45,261	26,162	127,385	74,327
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
REVENUES:	2,343,567	2,175,604	6,629,514	6,070,827
COST OF SALES:	1,995,252	1,853,668	5,624,527	5,142,382
GROSS PROFIT	348,315	321,936	1,004,987	928,445
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	247,054	220,142	712,265	660,321
DEPRECIATION AND AMORTIZATION EXPENSE	10,372	9,296	30,847	27,232
ASSET IMPAIRMENTS	204	4,252	702	5,973
INCOME FROM OPERATIONS	90,685	88,246	261,173	234,919
Floorplan interest expense	(8,963)	(8,544)	(26,439)	(25,489)
Interest Expense, Other	(12,738)	(12,264)	(38,534)	(34,326)
Loss on extinguishment of long-term debt		(22,790)		(46,403)
INCOME BEFORE INCOME TAXES	68,984	44,648	196,200	128,701
BENEFIT (PROVISION) FOR INCOME TAXES	(26,398)	(20,372)	(73,375)	(57,672)
EQUITY IN EARNINGS OF SUBSIDIARIES	0	0	0	0
NET INCOME	42,586	24,276	122,825	71,029
COMPREHENSIVE LOSS	(6,158)	2,366	(6,919)	(494)
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO PARENT	36,428	26,642	115,906	70,535
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
REVENUES:	457,002	450,844	1,330,389	1,328,122
COST OF SALES:	406,935	398,071	1,181,537	1,174,588
GROSS PROFIT	50,067	52,773	148,852	153,534
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	41,403	43,532	126,173	131,125
DEPRECIATION AND AMORTIZATION EXPENSE	1,439	1,450	4,594	4,192
ASSET IMPAIRMENTS	712	5,121	1,253	5,121
INCOME FROM OPERATIONS	6,513	2,670	16,832	13,096
Floorplan interest expense	(722)	(1,908)	(2,607)	(6,206)
Interest Expense, Other	(1,832)	(1,549)	(5,372)	(3,696)
Loss on extinguishment of long-term debt		0		0
INCOME BEFORE INCOME TAXES	3,959	(787)	8,853	3,194
BENEFIT (PROVISION) FOR INCOME TAXES	(1,342)	2,668	(3,814)	491
EQUITY IN EARNINGS OF SUBSIDIARIES	0	0	0	0
NET INCOME	2,617	1,881	5,039	3,685
COMPREHENSIVE LOSS	(36,307)	(21,938)	(56,902)	(7,329)
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO PARENT	(33,690)	(20,057)	(51,863)	(3,644)
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
REVENUES:	0	0	0	0
COST OF SALES:	0	0	0	0
GROSS PROFIT	0	0	0	0
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	0	0	0	0
DEPRECIATION AND AMORTIZATION EXPENSE	0	0	0	0
ASSET IMPAIRMENTS	0	0	0	0
INCOME FROM OPERATIONS	0	0	0	0
Floorplan interest expense	0	0	0	0
Interest Expense, Other	0	0	0	0
Loss on extinguishment of long-term debt		0		0
INCOME BEFORE INCOME TAXES	0	0	0	0
BENEFIT (PROVISION) FOR INCOME TAXES	0	0	0	0
EQUITY IN EARNINGS OF SUBSIDIARIES	(45,203)	(26,157)	(127,864)	(74,714)
NET INCOME	(45,203)	(26,157)	(127,864)	(74,714)
COMPREHENSIVE LOSS	0	0	0	0
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO PARENT	$ (45,203)	$ (26,157)	$ (127,864)	$ (74,714)