Future Payment Obligations Under Leases (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Leases Disclosure [Line Items]
2012	$ 7,460
2013	4,392
2014	3,814
2015	2,775
2016	1,260
2017 and thereafter	1,685
Lease Commitments Future Minimum Payments Due, Total	21,386
Operating Leases
Leases Disclosure [Line Items]
2012	7,286
2013	4,392
2014	3,814
2015	2,775
2016	1,260
2017 and thereafter	1,685
Lease Commitments Future Minimum Payments Due, Total	21,212
Idle Facility Leases
Leases Disclosure [Line Items]
2012	174
Lease Commitments Future Minimum Payments Due, Total	$ 174