Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Significant Accounting Policies [Abstract]

Property, Plant and Equipment [Table Text Block]

Lives of the assets are as follows:
	Years
Land improvements and buildings	5-30
Leasehold improvements	5-25
Furniture and fixtures	3-5
Shop and service equipment	3-10
Revenue equipment	5-7

Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block]

A reconciliation of the numerator (net income) and denominator (weighted average number of shares outstanding) of the basic and diluted earnings per share (“EPS”) for 2017, 2016, and 2015 is as follows (in thousands, except per share data):

	2017
	Net Income (numerator)		Shares (denominator)	Per Share Amount
Basic EPS	$	75,173	83,298	$	0.90
Effect of restricted stock	—		38
Diluted EPS	$	75,173	83,336	$	0.90

	2016
	Net Income (numerator)		Shares (denominator)	Per Share Amount
Basic EPS	$	56,386	83,297	$	0.68
Effect of restricted stock	—		68
Diluted EPS	$	56,386	83,365	$	0.68

	2015
	Net Income (numerator)		Shares (denominator)	Per Share Amount
Basic EPS	$	73,056	86,974	$	0.84
Effect of restricted stock	—		135
Diluted EPS	$	73,056	87,109	$	0.84