Commitments and Contingencies - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Contingencies And Commitments [Line Items]
Outstanding performance bonds to secure performance under certain contracts or state tax requirements	$ 20,926,000	$ 20,926,000
Minimum months of salary paid as severance		3 months
Maximum months of salary paid as severance		24 months
Recovered legal costs	$ 2,000,000