Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in accumulated other comprehensive income, net of tax
Balance at the beginning of period	$ 1,276
Other comprehensive loss	(2,707)	$ (4,463)	$ 719
Balance at the end of period	(1,431)	1,276
Foreign currency
Changes in accumulated other comprehensive income, net of tax
Balance at the beginning of period	1,920
Other comprehensive loss	(2,664)
Balance at the end of period	(744)	1,920
Defined benefit pension plan
Changes in accumulated other comprehensive income, net of tax
Balance at the beginning of period	(644)
Other comprehensive loss	(43)
Balance at the end of period	$ (687)	$ (644)