Note 2 - Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Property, Plant and Equipment [Table Text Block]

	2018			2017			Estimated Life (Years)
Land	$	134,873		$	129,805				–
Buildings and improvements		434,049			404,679			10	–	39
Leasehold improvements		27,165			26,765			2	–	39
Machinery and shop equipment		73,578			65,694			5	–	20
Furniture, fixtures and computers		67,330			63,475			3	–	15
Transportation equipment		92,385			81,158			2	–	15
Lease and rental vehicles		914,708			894,905			2	–	8
Construction in progress		16,310			8,043
Accumulated depreciation and amortization		(576,345	)		(514,929	)
Total	$	1,184,053		$	1,159,595

Schedule of Goodwill [Table Text Block]

Balance January 1, 2017	$	290,191
Acquisition		1,200
Balance December 31, 2017 and 2018	$	291,391

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2018			2017			2016
Expected stock volatility		31.68	%		33.54	%		35.63	%
Weighted-average stock volatility		31.68	%		33.54	%		35.63	%
Expected dividend yield		0.00	%		0.00	%		0.00	%
Risk-free interest rate		2.69	%		2.17	%		1.64	%
Expected life (years)		6.0			6.0			6.0
Weighted-average fair value of stock options granted	$	15.46		$	12.33		$	6.54