Summary of Significant Accounting Policies - Deferred Revenues and Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred revenue and costs
Deferred equipment revenue	$ 753	$ 883
Deferred fixed-priced support or maintenance contract revenue	3,811	4,265
Other deferred revenue	10,083	9,190
Total deferred revenue	14,647	14,338
Less current portion included in other accrued liabilities	14,647	14,304
Long-term portion of deferred revenue included in other liabilities	0	34
Current portion of deferred costs included in prepaid expenses and other	1,172	866
Long-term portion of deferred costs included in other assets	(72)	1,126
Total deferred costs	$ 1,100	$ 1,992