Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Percent				32.10%	21.40%
Acquired in-process research and development (Note 3)	$ 0.0	$ 0.0		$ 857.6	$ 0.0
Tax year under examination							2015	2014	2013	2012	2011	2010
Unrecognized tax benefits, decrease resulting from settlements			$ 140.0
Income taxes paid						$ 150.0