Office Closing and Termination Costs - Summary of Termination Costs (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Termination costs					$ 1,414
Building lease				$ 167	3,232	$ 3,200
Stock-based compensation					1,721
Total termination costs	$ 5	$ 417	$ 8,400	$ 167	$ 6,367