Per Share Information (Reconciliation of the Numerators and Denominators of the Basic and Diluted Per Share Computations) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Per Share Information
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		$ 210		$ 114
Dividends on preferred stock	[1]	(28)		(28)
Net income (loss) attributable to CCIC common stockholders for basic and diluted computations		$ 182		$ 86
Basic weighted-average number of common stock outstanding		415		409
Effect of assumed dilution from potential issuance of common shares relating to restricted stock units		2		1
Diluted weighted-average number of common shares outstanding		417		410
Basic		$ 0.44		$ 0.21
Diluted		0.44		0.21
Common Stock, Dividends, Per Share, Declared		1.125		1.05
Preferred Stock, Dividends Per Share, Declared		$ 17.1875	$ 17.1875	$ 17.1875

[1] See note 7 for information regarding common and preferred stock dividends declared per share.