Restructuring and Other Special Charges and Related Liability Balances (Detail) (Restructuring November 2012 Plan, USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Restructuring Cost and Reserve [Line Items]
Accrual, Beginning Balance	$ 5,248
Cash Payments	(1,817)
Accrual, Ending Balance	3,431
Workforce reduction
Restructuring Cost and Reserve [Line Items]
Accrual, Beginning Balance	1,057
Cash Payments	(420)
Accrual, Ending Balance	637
Consolidation of office facilities
Restructuring Cost and Reserve [Line Items]
Accrual, Beginning Balance	4,063
Cash Payments	(1,275)
Accrual, Ending Balance	2,788
Other costs and professional fees
Restructuring Cost and Reserve [Line Items]
Accrual, Beginning Balance	128
Cash Payments	(122)
Accrual, Ending Balance	$ 6