Employee Benefit Plans - Combined Amount Of Net Periodic Benefit Cost Recognized (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Components of net periodic pension benefit cost
Service cost	$ 0.6	$ 0.7
Interest cost	1.2	1.2
Expected return on plan assets	(1.6)	(1.7)
Amortization of actuarial gains	0.2	0.3
Amortization of prior service costs	(0.1)	0.0
Net periodic cost	$ 0.3	$ 0.5