Condensed Consolidated Statements of Cash Flows (Unaudited) (Parentheticals) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Statement of Cash Flows [Abstract]
Restricted cash	$ 1.0	$ 8.7	$ 6.4
Restricted cash, current	0.0	7.7	5.4
Restricted cash, noncurrent	$ 1.0	$ 1.0	$ 1.0