Annual report pursuant to Section 13 and 15(d)

Consolidated Statements of Comprehensive Income (Parenthetical)

v3.8.0.1
Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Statement of Comprehensive Income [Abstract]      
Unrealized gain (loss) on available-for-sale securities, (provision) benefit $ 0.1 $ 0.0 $ 0.2
Unrealized gain (loss) on interest rate swaps, tax (provision) benefit $ 0.0 $ 0.0 $ 0.0