Operating Segments - Geographic Segments (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Segment Reporting Information [Line Items]                      
Revenues $ 42,745 $ 41,208 $ 42,618 $ 40,235 $ 40,096 $ 38,105 $ 26,296 $ 18,795 $ 166,806 $ 123,292 $ 72,140
Long-Lived Assets 75,377       70,767       75,377 70,767 44,114
United States                      
Segment Reporting Information [Line Items]                      
Revenues                 138,510 110,392 72,140
Long-Lived Assets 70,208       63,858       70,208 63,858 44,045
Other                      
Segment Reporting Information [Line Items]                      
Revenues                 28,296 12,900 0
Long-Lived Assets $ 5,169       $ 6,909       $ 5,169 $ 6,909 $ 69