Income Per Common Share - Computations of Basic and Diluted Income (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended						9 Months Ended
		Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share Reconciliation [Abstract]
Net income		$ 49,430	$ 30,231	$ 481,447	$ 373,087	$ 452,855	$ (456,808)	$ 561,108	$ 369,134
Participating earnings	[1]	(632)			(8,667)			(10,868)	(9,183)
Basic net income attributed to common shareholders		48,798			364,420			550,240	359,951
Reallocation of participating earnings	[1]	4			172			106	188
Diluted net income attributed to common shareholders		$ 48,802			$ 364,592			$ 550,346	$ 360,139
Net income per common share:
Basic		$ 0.2			$ 1.52			$ 2.3	$ 1.48
Diluted		$ 0.2			$ 1.49			$ 2.27	$ 1.45

[1] (a) Restricted Stock Liability Awards represent participating securities because they participate in nonforfeitable dividends or distributions with common equity owners. Income allocable to participating securities represents the distributed and undistributed earnings attributable to the participating securities. Participating securities, however, do not participate in undistributed net losses.