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Equity And Earnings Per Share (Basic Table) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basic earnings per share:
Net income available for common stockholders	$ 46	$ 24
Weighted average shares of common stock outstanding:
Weighted Average Number of Shares Outstanding, Basic	71,475,950	67,985,107
Basic earnings per share	$ 0.64	$ 0.35
Common Class A
Weighted average shares of common stock outstanding:
Weighted Average Number of Shares Outstanding, Basic	71,475,850	67,985,007
Common Class B
Weighted average shares of common stock outstanding:
Weighted Average Number of Shares Outstanding, Basic	100	100

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