Restructuring Charge - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			0 Months Ended	9 Months Ended
	Sep. 30, 2014 Employee	Sep. 30, 2013	Sep. 30, 2014 Employee	Sep. 30, 2013	Dec. 31, 2013	May 30, 2014 Special Termination Benefits [Member]	Sep. 30, 2014 Special Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Total number of employees affected by restructuring initiatives	180		180
Restructuring charge	$ 0	$ 400,000	$ 700,000	$ 1,800,000
Cumulative cost of restructuring to date	19,600,000		19,600,000		18,900,000
Contractual termination range of dates							Agreed to terminate him on either March 31, 2014, April 30, 2014 or May 31, 2014, at the Company's discretion.
Cost of severance and termination benefits						$ 800,000