Stock Repurchases, Dividends and Earnings per Share - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
1 Months Ended | 3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|---|
Jul. 31, 2016 |
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
Dec. 31, 2015 |
|
| Equity [Abstract] | ||||||
| Stock repurchased and pending settlement (in shares) | 0.2 | 0.1 | 0.2 | 0.1 | ||
| Stock repurchased and pending settlement, liability | $ 9.1 | $ 5.3 | $ 9.1 | $ 5.3 | ||
| Quarterly dividend declared (in dollars per share) | $ 0.32 | $ 0.32 | $ 0.3 | $ 0.92 | $ 0.86 | |
| Cash dividends declared | $ 315.2 | |||||
| Quarterly dividend payable | $ 109.0 | $ 109.0 | $ 103.7 | |||