Annual report pursuant to Section 13 and 15(d)

Segment Data and Revenue by Geographic Area - Schedule of Revenue by Geographic Area (Details)

v3.8.0.1
Segment Data and Revenue by Geographic Area - Schedule of Revenue by Geographic Area (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Segment Reporting Information [Line Items]                      
Revenues $ 395,335 $ 378,639 $ 376,834 $ 316,004 $ 392,598 $ 351,901 $ 343,022 $ 297,305 $ 1,466,812 $ 1,384,826 $ 1,164,043
United States                      
Segment Reporting Information [Line Items]                      
Revenues                 1,456,673 1,366,330 1,155,210
International                      
Segment Reporting Information [Line Items]                      
Revenues                 $ 10,139 $ 18,496 $ 8,833