Lease Exit and Related Charges (Changes to Accrued Loss on Excess Office Facilities) (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Sep. 30, 2015	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Disclosure Changes To Accrued Loss On Excess Office Facilities [Abstract]
Lease exit and related charges	$ 127		$ 9	$ 958	$ 87
Percent reduction in office space		43.00%
Accrued Loss on Excess Office Facilities [Roll Forward]
Accrued loss at December 31, 2015				2,595
Additions and adjustments to the lease loss accrual, including estimated sublease income				831
Less amounts paid, net of sublease amounts				(877)
Accrued loss at June 30, 2016	2,549			2,549
Less current portion (included in Accrued and other current liabilities)	(1,227)			(1,227)
Accrued loss, non-current portion (included in Other long term liabilities)	$ 1,322			$ 1,322