Expected and Actual Cash Charges and Non-Cash Charges (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Restructuring Cost and Reserve [Line Items]
Total restructuring costs	$ 6,057	$ 1,967
Cumulative Costs for Plan	8,024
Expected Cumulative Costs	9,400
Cash Charges
Restructuring Cost and Reserve [Line Items]
Total restructuring costs	4,109	1,061
Cumulative Costs for Plan	5,170
Expected Cumulative Costs	6,400
Non-Cash Charges
Restructuring Cost and Reserve [Line Items]
Total restructuring costs	1,948	906
Cumulative Costs for Plan	2,854
Expected Cumulative Costs	$ 3,000