Accounts Receivable, Notes Receivable, Allowance for Doubtful Accounts and Bad Debt - Current and Long-Term (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current:
Accounts receivable	$ 360.4	$ 221.1
Notes receivable	164.3	10.3
Allowance for doubtful accounts	(20.0)	(11.2)
Current accounts and notes receivable, net	504.7	220.2
Long-term:
Long-term notes receivable	72.6	0
Total accounts and notes receivable, net	$ 577.3	$ 220.2