Income (Loss) Per Common Share - Basic Weighted Average Common Shares Outstanding to Diluted Weighted Average Common Shares Outstanding (Detail) - shares shares in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Weighted average common shares outstanding – basic	[1]	245,177	167,126	244,916	166,964
Effect of dilutive securities:
Director and employee PSUs and RSUs		158	0	326	0
Weighted average common shares outstanding – diluted		245,335	167,126	245,242	166,964

[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.