Equity (Details) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($) $ / shares shares	Sep. 30, 2019 USD ($) $ / shares shares
Class of Stock [Line Items]
Total cost | $	$ 2,700.0	$ 502.5
Remaining authorized for share repurchases | $	$ 66.4	$ 66.4
Class A
Class of Stock [Line Items]
Shares repurchased (in shares) | shares	24,002,262	346,300
Average price paid per share (in dollars per share) | $ / shares	$ 27.50	$ 25.10
Class C
Class of Stock [Line Items]
Shares repurchased (in shares) | shares	75,420,009	19,975,282
Average price paid per share (in dollars per share) | $ / shares	$ 27.00	$ 24.72