Revenue Recognition - Applicable Accounting Guidance for Revenue (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Equipment rental	$ 346.7	$ 340.7
Total other rental revenues	30.9	28.4
Total equipment rentals	377.6	369.1
Sales of rental equipment	85.1	47.3
Sales of new equipment, parts and supplies	10.9	11.4
Service and other revenue	2.1	3.5
Total revenues	475.7	431.3
ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Equipment rental	346.7
Total other rental revenues	11.0
Total equipment rentals	357.7
Sales of rental equipment	0.0
Sales of new equipment, parts and supplies	0.0
Service and other revenue	0.0
Total revenues	357.7
ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Equipment rental	0.0	0.0
Total other rental revenues	19.9	17.2
Total equipment rentals	19.9	17.2
Sales of rental equipment	85.1	47.3
Sales of new equipment, parts and supplies	10.9	11.4
Service and other revenue	2.1	3.5
Total revenues	118.0	79.4
Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Equipment rental		340.7
Total other rental revenues		11.2
Total equipment rentals		351.9
Sales of rental equipment		0.0
Sales of new equipment, parts and supplies		0.0
Service and other revenue		0.0
Total revenues		351.9
Delivery and Pick-up
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total other rental revenues	19.9	17.2
Delivery and Pick-up \| ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total other rental revenues	0.0
Delivery and Pick-up \| ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total other rental revenues	19.9	17.2
Delivery and Pick-up \| Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total other rental revenues		0.0
Other Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total other rental revenues	11.0	11.2
Other Revenue \| ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total other rental revenues	11.0
Other Revenue \| ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total other rental revenues	$ 0.0	0.0
Other Revenue \| Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total other rental revenues		$ 11.2