Minimum Lease Commitments Under Non Cancellable Operating Lease (Detail) (Noncancelable Lease Obligations, USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Lease Commitments And Contingencies [Line Items]
2013	$ 7,028
2014	6,364
2015	4,265
2016	3,709
2017	2,738
Thereafter	7,581
Total	31,685
Affiliated Entity
Lease Commitments And Contingencies [Line Items]
2013	3,262
2014	3,171
2015	2,910
2016	2,486
2017	1,670
Thereafter	1,045
Total	14,544
Other Affiliates
Lease Commitments And Contingencies [Line Items]
2013	3,766
2014	3,193
2015	1,355
2016	1,223
2017	1,068
Thereafter	6,536
Total	$ 17,141