Segment Information Foreign Currency Exchange Rates (Details)	Sep. 30, 2018 $ / $	Sep. 30, 2018 $ / £	Sep. 30, 2018 $ / $	Sep. 30, 2018 $ / €	Dec. 31, 2017 $ / $	Dec. 31, 2017 $ / £	Dec. 31, 2017 $ / $	Dec. 31, 2017 $ / €	Sep. 30, 2017 $ / $	Sep. 30, 2017 $ / £	Sep. 30, 2017 $ / $	Sep. 30, 2017 $ / €	May 03, 2017 $ / £
Foreign currency exchange rate													1.29
Last day rate [Member]
Foreign currency exchange rate	0.72	1.30	0.77	1.16	0.78	1.35	0.80	1.20
Quarter to Date Average [Member]
Foreign currency exchange rate	0.73	1.30	0.77	1.16					0.79	1.31	0.80	1.17
Year to Date Average [Member]
Foreign currency exchange rate	0.76	1.35	0.78	1.19					0.77	1.28	0.77	1.11