Commitments and Contingencies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Nov. 19, 2007
Chase [Member]
Commitments And Contingencies [Line Items]
Comprehensive Medical Plans, Stop loss policy deductible	$ 100
Maximum comprehensive Medical Plans, Stop loss policy deductible	2,000
Annual workers' compensation costs		500
Global Brass and Copper Employees Excluding Chase [Member]
Commitments And Contingencies [Line Items]
Comprehensive Medical Plans, Stop loss policy deductible	$ 275