(Loss) Income Per Common Share - Basic Weighted Average Common Shares Outstanding to Diluted Weighted Average Common Shares Outstanding (Detail) - shares shares in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Weighted average common shares outstanding – basic	[1]	245,244	180,683	245,027	171,571
Effect of dilutive securities:
Director and employee PSUs and RSUs		0	0	253	0
Weighted average common shares outstanding – diluted		245,244	180,683	245,280	171,571

[1] 2017 includes common stock issued in connection with the exchange of 77.0 million shares for all outstanding Memorial common stock on September 16, 2016.