Loss on Exit and Related Charges (Changes to Accrued Loss on Excess Office Facilities) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013 term	Dec. 31, 2012
Disclosure Changes To Accrued Loss On Excess Office Facilities [Abstract]
Leases term		11 years
Number of extensions on lease		2
Lease extension term		5 years
Cash paid for contract termination fees		$ 6,500,000
Accrued Loss on Excess Office Facilities [Roll Forward]
Accrued loss, beginning of year	254,000	4,213,000	2,747,000
Additions and adjustments to the lease loss accrual, including sublease income estimate revision, and related asset write-downs	668,000	1,421,000	3,290,000
Less write-down of leasehold improvements	0	0	(496,000)
Less amounts paid, net of sublease income	(688,000)	(5,380,000)	(1,328,000)
Accrued loss, end of year	234,000	254,000	4,213,000
Less current portion (included in Accrued and other current liabilities)	(234,000)	(254,000)	(2,463,000)
Accrued loss, non-current portion	$ 0	$ 0	$ 1,750,000