- Components of Other Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Intangible Assets by Major Class [Line Items]
Amortizable, Gross Carrying Amount	$ 191,425	$ 86,880
Accumulated Amortization	(49,130)	(33,728)	$ (23,158)
Amortizable, Net	142,295	53,152
Total other intangible assets, Gross Carrying Amount	420,546	138,831	$ 124,093
Total other intangible assets, net	$ 371,416	$ 105,103
Non-compete agreements
Intangible Assets by Major Class [Line Items]
Total Estimated Life (years)	5 years	5 years
Amortizable, Gross Carrying Amount	$ 540	$ 540
Accumulated Amortization	(485)	(401)
Amortizable, Net	55	$ 139
Dealer/customer related
Intangible Assets by Major Class [Line Items]
Total Estimated Life (years)		7 years
Amortizable, Gross Carrying Amount	164,837	$ 67,079
Accumulated Amortization	(35,907)	(24,069)
Amortizable, Net	$ 128,930	43,010
Dealer/customer related | Minimum
Intangible Assets by Major Class [Line Items]
Total Estimated Life (years)	5 years
Dealer/customer related | Maximum
Intangible Assets by Major Class [Line Items]
Total Estimated Life (years)	10 years
Developed technology
Intangible Assets by Major Class [Line Items]
Amortizable, Gross Carrying Amount	$ 26,048	19,261
Accumulated Amortization	(12,738)	(9,258)
Amortizable, Net	$ 13,310	$ 10,003
Developed technology | Minimum
Intangible Assets by Major Class [Line Items]
Total Estimated Life (years)	5 years	5 years
Developed technology | Maximum
Intangible Assets by Major Class [Line Items]
Total Estimated Life (years)	7 years	7 years
Non-amortizable—brand/trade names
Intangible Assets by Major Class [Line Items]
Non-amortizable, Gross Carrying Amount	$ 229,121	$ 51,951
Non-amortizable, Net	$ 229,121	$ 51,951