Annual report pursuant to Section 13 and 15(d)

Business Segments and Customer Information - Geographic Area (Details)

v3.20.1
Business Segments and Customer Information - Geographic Area (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Revenues $ 195,271 $ 198,326 $ 189,111 $ 169,919 $ 180,996 $ 168,931 $ 170,394 $ 176,897 $ 752,627 $ 697,218 $ 760,113
United States                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Revenues                 659,451 647,168 708,474
Other Countries                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Revenues                 $ 93,176 $ 50,050 $ 51,639