Summary of Exit Costs (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended	20 Months Ended
	Dec. 31, 2011	Dec. 31, 2011
Restructuring Cost and Reserve [Line Items]
Total Amount Expected to be Incurred	$ 7,100
Amount Incurred during the period	1,348
Cumulative Amounts Incurred through the period end date		6,812
Termination benefits
Restructuring Cost and Reserve [Line Items]
Total Amount Expected to be Incurred	6,000
Amount Incurred during the period	980
Cumulative Amounts Incurred through the period end date		5,823
Other associated costs
Restructuring Cost and Reserve [Line Items]
Total Amount Expected to be Incurred	1,100
Amount Incurred during the period	368
Cumulative Amounts Incurred through the period end date		$ 989