Summary of Significant Accounting Policies - Deferred Revenues and Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred revenue and costs
Deferred equipment revenue	$ 2,718	$ 753
Deferred fixed-priced support or maintenance contract revenue	4,527	3,811
Other deferred revenue	16,246	10,083
Total deferred revenue	23,491	14,647
Less current portion included in other accrued liabilities	21,400	14,647
Long-term portion of deferred revenue included in other liabilities	2,091	0
Current portion of deferred costs included in prepaid expenses and other	784	1,172
Long-term portion of deferred costs included in other assets	1,297	(72)
Total deferred costs	$ 2,081	$ 1,100