Goodwill and Acquired Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Changes in Carrying Amount of Goodwill

The changes in the carrying amount of goodwill for the two years ended December 31, 2017 are as follows (in thousands):

Balance as of December 31, 2015	$	45,346
Goodwill adjustments	166
Foreign currency translation adjustments	(165		)
Balance as of December 31, 2016	45,347
Goodwill acquired	13,350
Foreign currency translation adjustments	434
Balance as of December 31, 2017	$	59,131

Summary of Intangible Assets Acquired

The following tables present information about our acquired intangible assets subject to amortization as of December 31, 2017 and 2016 (in thousands):

	As of December 31, 2017
	Cost		Accumulated Amortization			Foreign Currency Translation Adjustments			Net		Weighted Average Remaining Useful Life
											(In years)
Developed technology	$	17,200	$	(9,835	)	$	(93	)	$	7,272	3.7
Customer relationships	2,210		(1,549		)	(30		)	631		2.4
	$	19,410	$	(11,384	)	$	(123	)	$	7,903

	As of December 31, 2016
	Cost		Accumulated Amortization			Foreign Currency Translation Adjustments			Net		Weighted Average Remaining Useful Life
											(In years)
Developed technology	$	14,000	$	(6,584	)	$	(169	)	$	7,247	2.9
Customer relationships	1,800		(1,044		)	(53		)	703		2.3
	$	15,800	$	(7,628	)	$	(222	)	$	7,950

Summary of Estimated Future Amortization Expense

Estimated future amortization expense as of December 31, 2017 is as follows (in thousands): 

2018	$	2,727
2019	2,678
2020	1,103
2021	492
2022	492
Thereafter	411
	$	7,903