Income (Loss) Per Common Share - Basic Weighted Average Common Shares Outstanding and Diluted Weighted Average Common Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Weighted Average Number Of Shares Outstanding [Abstract]
Weighted average common shares outstanding - basic and diluted	243,311	239,895	242,692	241,770

Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

No definition available.

Name:	us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration