Segment Information Foreign Currency Exchange Rates (Details)	Mar. 31, 2019 $ / £	Mar. 31, 2019 $ / €	Mar. 31, 2019 $ / $	Mar. 31, 2019 $ / $	Dec. 31, 2018 $ / £	Dec. 31, 2018 $ / €	Dec. 31, 2018 $ / $	Dec. 31, 2018 $ / $	Mar. 31, 2018 $ / £	Mar. 31, 2018 $ / €	Mar. 31, 2018 $ / $	Mar. 31, 2018 $ / $
Last day rate [Member]
Foreign Currency Exchange Rate, Translation	1.30	1.12	0.71	0.75	1.28	1.15	0.70	0.73
Quarter to Date Average [Member]
Foreign Currency Exchange Rate, Translation	1.30	1.14	0.71	0.75					1.39	1.23	0.79	0.79