Restructuring Activity and Balances (Detail) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011
Restructuring Cost and Reserve [Line Items]
Restructuring Liability beginning of period	$ 7,964
Initial Restructuring Charges	318
Subsequent Plan Adjustments	1,151
Cash Payments	(1,832)
Restructuring Liability end of period	7,601
Activity for 2011 restructuring charge
Restructuring Cost and Reserve [Line Items]
Initial Restructuring Charges	318
Subsequent Plan Adjustments	26
Cash Payments	(67)
Restructuring Liability end of period	277
Activity for 2010 restructuring charge
Restructuring Cost and Reserve [Line Items]
Restructuring Liability beginning of period	12
Cash Payments	(12)
Activity for 2007 restructuring charge
Restructuring Cost and Reserve [Line Items]
Restructuring Liability beginning of period	5,635
Subsequent Plan Adjustments	720
Cash Payments	(1,216)
Restructuring Liability end of period	5,139
Activity for 2001 restructuring charge
Restructuring Cost and Reserve [Line Items]
Restructuring Liability beginning of period	2,317
Subsequent Plan Adjustments	405
Cash Payments	(537)
Restructuring Liability end of period	$ 2,185