Stockholders' Equity and EPS - Stock Repurchase Program (Details) - USD ($) shares in Millions	6 Months Ended
Jun. 30, 2019	Nov. 13, 2018
Equity and Earnings Per Share [Abstract]
Amount of outstanding common stock approved to be repurchased		$ 500,000,000
Common stock repurchased and retired (in shares)	1.0
Common stock repurchased and retired	$ 230,800,000
Cumulative stock repurchased and retired (in shares)	2.2
Cumulative stock repurchased and retired	$ 493,900,000

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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Period Type:	duration