Fair Value Measurements - Summary of Changes in the Fair Value of the Contingent Consideration Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Payment of contingent consideration	$ (816)	$ (513)
Fair value adjustment of contingent consideration	(92)	228
NLEX [Member] | Contingent Consideration [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	3,457	4,198
Payment of contingent consideration	(816)	(513)
Fair value adjustment of contingent consideration	92	(228)
Ending balance	$ 2,733	$ 3,457