Costs Associated With Restructuring Activities - Narrative (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Restructuring and Related Activities [Abstract]        
Restructuring charges $ 0 $ 3,264,000 $ 0 $ 5,726,000