Pre-Tax Charges and Changes in Restructuring Reserves (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Restructuring Reserve Disclosures [Abstract]
Beginning Reserve	$ 2,052	$ 672
Charges during period	2,319	8,371
Cash Paid	(3,478)	(2,800)
Ending Reserve	893	2,052
Employee severance
Restructuring Reserve Disclosures [Abstract]
Beginning Reserve	1,835	666
Charges during period	1,078	3,100
Cash Paid	(2,583)	(1,931)
Ending Reserve	330	1,835
Other costs
Restructuring Reserve Disclosures [Abstract]
Beginning Reserve	217	6
Charges during period	1,241	1,080
Cash Paid	(895)	(869)
Ending Reserve	563	217
Non-cash items | Employee severance
Restructuring Reserve Disclosures [Abstract]
Beginning Reserve		0
Charges during period		3,266
Cash Paid		0
Ending Reserve		0
Non-cash items | Other costs
Restructuring Reserve Disclosures [Abstract]
Beginning Reserve		0
Charges during period		925
Cash Paid		0
Ending Reserve		$ 0