Accident and Workers' Compensation Insurance Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Accident and Workers' Compensation Insurance Liabilities [Line Items]
Auto liability retention limit	$ 2.0
Excess Insurance Coverage Limit	75.0
Workers compensation retention limit	1.0
Trust fund requirements	0.7
Restricted Cash and Cash Equivalents, Noncurrent	10.5
Letters of Credit Outstanding, Amount	8.7
Gordon Trucking Company, Inc [Member]
Accident and Workers' Compensation Insurance Liabilities [Line Items]
Auto liability retention limit	0.5
Excess Insurance Coverage Limit	75.0
Workers compensation retention limit	0.5
Trust fund requirements	0.7
Restricted Cash and Cash Equivalents, Noncurrent	$ 0.6