Special Charges - Additional Information (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($) Employee	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Other Income And Expenses [Abstract]
Special charges	$ 5,061
Number of employees terminated for future growth | Employee	53
Total cash outflow associated with special charges, amount expected to be paid	$ 4,900		$ 65,500	$ 65,500	$ 65,500
Cash outflow associated with special charges, amount paid	2,300	$ 54,300
Cash outflow associated with special charges, amount expected to be paid in remainder of 2016	2,300
Cash outflow associated with special charges, amount expected to be paid in 2017	300
Total expected payments to special charges, amount expected to be paid in 2016	2,700
Total expected payments to special charges, amount expected to be paid in 2017	3,100
Total expected payments to special charges, amount expected to be paid in 2018	2,600
Total expected payments to special charges, amount expected to be paid in 2019	1,200
Total expected payments to special charges, amount expected to be paid from 2020 to 2026	$ 1,600