Fair Value Measurements - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Fair Value Measurements, Inter-transfers between Levels	$ 0	$ 0
Minimum [Member]
Business Combination Contingent Consideration Liability Extended Term	3 years
Maximum [Member]
Business Combination Contingent Consideration Liability Extended Term	6 years