Segment Reporting - Long-lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment reporting
Long-lived Assets	$ 126,090	$ 133,971	$ 146,724
United States
Segment reporting
Long-lived Assets	92,509	97,226	107,746
Canada
Segment reporting
Long-lived Assets	6,972	6,357	7,070
Europe
Segment reporting
Long-lived Assets	22,883	27,226	29,531
Asia Pacific
Segment reporting
Long-lived Assets	$ 3,726	$ 3,162	$ 2,377