Commitments, Contingencies & Guarantees - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended			22 Months Ended
	Sep. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 31, 2015
Loss Contingencies [Line Items]
Rent expense		$ 12.9	$ 13.2	$ 11.5
Incentive awarded to the company by the State of Connecticut, total		11.5
Incentive awarded to the company by the State of Connecticut, non-interest bearing loans	$ 6.0	8.0
Incentive awarded to the company by the State of Connecticut, grants	1.5	$ 3.5
Non-interest bearing incentive loan term		10 years
Incentive awarded to the company by the State of Connecticut, deferred revenue	$ 7.5	$ 6.3	6.1
Forgiveness awarded to the company by the state of Connecticut		6.0			$ 6.0
Additional forgiveness awarded to the company by the state of Connecticut		1.0			1.0
Forgiveness awarded to the company by the State of Connecticut, grants		0.5			$ 0.5
Incentive awarded to the company by the State of Connecticut, revenue recognized		$ 1.4	$ 1.1	$ 0.3
Maximum
Loss Contingencies [Line Items]
Non-cancellable operating leases expiration year		2030