Quarterly report pursuant to Section 13 or 15(d)

Intangible Assets (Details)

v3.19.1
Intangible Assets (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Schedule Of Intangible Assets [Line Items]    
Intangible assets subject to amortization, Gross Carrying Amount $ 120,750 $ 123,368
Intangible assets subject to amortization, Accumulated Amortization (96,634) (94,630)
Intangible assets subject to amortization, Net Carrying Amount 24,116 28,738
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 (96,359) (91,756)
Intangible assets subject to amortization, Net Carrying Amount $ 23,641 $ 28,244
Weighted- Average Amortization Period (Years) 6 years 6 years
Licenses    
Schedule Of Intangible Assets [Line Items]    
Intangible assets subject to amortization, Gross Carrying Amount $ 750 $ 3,368
Intangible assets subject to amortization, Accumulated Amortization (275) (2,874)
Intangible assets subject to amortization, Net Carrying Amount $ 475 $ 494
Weighted- Average Amortization Period (Years) 10 years 5 years 7 months 6 days