Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Commitment And Contingencies [Line Items]
Surety bonds, issued and outstanding	$ 61,200,000
Letters of credit, issued and outstanding	14,700,000
Letter of credit facilities	65,000,000
Adjustments	8,000,000	8,011,000
Cash payments	226,000	14,450,000	2,760,000
Legal accruals	2,300,000	9,400,000
Legal recoveries	9,800,000
Non-cancelable operating leases	6,600,000	7,700,000	8,700,000
HomeAmerican [Member]
Commitment And Contingencies [Line Items]
Letters of credit, issued and outstanding	6,700,000
Estimated cost to related to bonds	24,200,000
Estimated cost to related to letters of credit	$ 6,500,000