Schedule of Commitments and Obligations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Commitment And Contingencies [Line Items]
Total	$ 225,231
Less than 1 year	182,555
1 to 3 years	40,245
3 to 5 years	481
More than 5 years	1,950
Purchase Obligations
Commitment And Contingencies [Line Items]
Total	108,977
Less than 1 year	72,685
1 to 3 years	35,855
3 to 5 years	437
Guarantees
Commitment And Contingencies [Line Items]
Total	84,667
Less than 1 year	83,879
1 to 3 years	788
Letters Of Credit
Commitment And Contingencies [Line Items]
Total	31,587
Less than 1 year	25,991
1 to 3 years	3,602
3 to 5 years	44
More than 5 years	$ 1,950