Background and Basis of Presentation - Initial Public Offering (Details) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Jul. 29, 2015	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Noncontrolling Interest [Line Items]
Proceeds from initial public offering, net		$ 265.0
Proceeds from the issuance of common stock to underwriters, net	$ 7.8		$ 294.0	$ 1.8	$ 290.6
IPO [Member]
Noncontrolling Interest [Line Items]
Shares sold, initial public offering (in shares)	415,600	14,285,714
Shares sold, initial public offering, price per share (in dollars per share)	$ 20.00	$ 20