Restructuring Activity and Balances (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring Liability beginning of period	$ 7,593
Cash Payments	(661)
Restructuring Liability end of period	6,932
Activity for 2011 restructuring charge | Real estate obligations
Restructuring Cost and Reserve [Line Items]
Restructuring Liability beginning of period	361
Cash Payments	(76)
Restructuring Liability end of period	285
Activity for 2007 restructuring charge | Real estate obligations
Restructuring Cost and Reserve [Line Items]
Restructuring Liability beginning of period	5,162
Cash Payments	(387)
Restructuring Liability end of period	4,775
Activity for 2001 restructuring charge | Real estate obligations
Restructuring Cost and Reserve [Line Items]
Restructuring Liability beginning of period	2,070
Cash Payments	(198)
Restructuring Liability end of period	$ 1,872