Goodwill and Other Intangible Assets Components of Other Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Amortizable:
Gross amortized other intangible assets	$ 522,721	$ 522,354
Accumulated Amortization	(113,876)	(94,136)
Net amortized other intangible assets	408,845	428,218
Total other intangible assets, net	$ 851,066	870,517
Non-compete agreements
Amortizable:
Total estimated life	4 years
Gross amortized other intangible assets	$ 2,630	2,630
Dealer/customer related
Amortizable:
Gross amortized other intangible assets	$ 506,780	506,401
Dealer/customer related | Minimum
Amortizable:
Total estimated life	5 years
Dealer/customer related | Maximum
Amortizable:
Total estimated life	20 years
Developed technology
Amortizable:
Gross amortized other intangible assets	$ 13,311	13,323
Developed technology | Minimum
Amortizable:
Total estimated life	5 years
Developed technology | Maximum
Amortizable:
Total estimated life	7 years
Brand/trade names
Non-amortizable—indefinite lived:
Non-amortizable, Net	$ 442,221	$ 442,299