Quarterly report pursuant to Section 13 or 15(d)

Intangible Assets (Details)

v3.10.0.1
Intangible Assets (Details) - USD ($)
$ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2018
Dec. 31, 2017
Jan. 01, 2018
Schedule Of Intangible Assets [Line Items]      
Intangible assets subject to amortization, Gross Carrying Amount $ 123,368 $ 124,028 $ 124,028
Intangible assets subject to amortization, Accumulated Amortization (81,524) (69,127) (69,127)
Intangible assets subject to amortization, Net Carrying Amount 41,844 54,901 $ 54,901
Customer relationships      
Schedule Of Intangible Assets [Line Items]      
Intangible assets subject to amortization, Gross Carrying Amount 120,000 120,000  
Intangible assets subject to amortization, Accumulated Amortization (79,311) (66,866)  
Intangible assets subject to amortization, Net Carrying Amount $ 40,689 $ 53,134  
Weighted- Average Amortization Period (Years) 6 years 6 years  
Licenses      
Schedule Of Intangible Assets [Line Items]      
Intangible assets subject to amortization, Gross Carrying Amount $ 3,368 $ 3,368  
Intangible assets subject to amortization, Accumulated Amortization (2,213) (1,601)  
Intangible assets subject to amortization, Net Carrying Amount $ 1,155 $ 1,767  
Weighted- Average Amortization Period (Years) 5 years 7 months 6 days 5 years 7 months 6 days  
Non-compete agreements      
Schedule Of Intangible Assets [Line Items]      
Intangible assets subject to amortization, Gross Carrying Amount   $ 660  
Intangible assets subject to amortization, Accumulated Amortization   (660)  
Intangible assets subject to amortization, Net Carrying Amount   $ 0  
Weighted- Average Amortization Period (Years)   1 year