Related Party Transactions - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2008	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Related Party Transactions [Abstract]
Duration of lease	20 years
Payment to landlord under the lease terms		$ 0.1	$ 0.1	$ 0.2	$ 0.2