Environmental Commitments and Contingencies - Additional Information 1 (Detail) (USD $)	3 Months Ended
	Mar. 31, 2013
Key West Florida [Member]
Environmental Commitments And Contingencies [Line Items]
Costs to resolve liability	$ 50,000
Period of regulatory inactivity	17 years
Key West Florida [Member] | Maximum [Member]
Environmental Commitments And Contingencies [Line Items]
Costs to resolve liability	8,000
Pensacola Florida [Member] | Maximum [Member]
Environmental Commitments And Contingencies [Line Items]
Costs to resolve liability	5,000
Salisbury Maryland [Member]
Environmental Commitments And Contingencies [Line Items]
Monitoring well remaining maximum cost	5,000
Winter Haven Florida [Member]
Environmental Commitments And Contingencies [Line Items]
Environmental Remediation Expense	443,000
Additional remediation costs	100,000
Corrective measures cost	1,000,000
Winter Haven Florida [Member] | Maximum [Member]
Environmental Commitments And Contingencies [Line Items]
Remedial action time period	3 years
Winter Haven Florida [Member] | Minimum [Member]
Environmental Commitments And Contingencies [Line Items]
Remedial action time period	2 years
Sanford Florida [Member]
Environmental Commitments And Contingencies [Line Items]
Environmental Remediation Expense	24,000
Estimated costs of remediation range, maximum	13,000,000
Costs to resolve liability	$ 650,000