Supplemental Financial Statement Information - Cash and Cash Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash and Cash Equivalents [Abstract]
Cash	$ 149.3	$ 267.7
Other short-term investments	0.5	1.8
Total cash and cash equivalents	$ 149.8	$ 269.5	$ 1,026.8	$ 304.6