Annual report pursuant to Section 13 and 15(d)

Operating Leases - Narrative (Details)

v3.10.0.1
Operating Leases - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Leases [Abstract]      
Rent expense $ 11.0 $ 10.1 $ 8.5
Termination fee to cancel sublease before end of term $ 2.5