Earnings per Share - Schedule Of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 12,338	$ 28,034	$ 36,055	$ 43,674	$ 31,163	$ 42,239	$ 39,806	$ 23,232	$ 120,101	$ 136,440	$ 124,150
Preferred stock dividends									41	42	42
Net income available to common equity									120,060	136,398	124,108
Dividends and undistributed earnings allocated to participating securities									(84)	(183)	(117)
Net income available to common shareholders									$ 119,976	$ 136,215	$ 123,991
Basic weighted-average shares outstanding									38,885	38,653	38,362
Stock options and other stock compensation									401	536	599
Diluted weighted-average shares outstanding									39,286	39,189	38,961
Earnings per share:
Basic (dollars per share)	$ 0.32	$ 0.72	$ 0.93	$ 1.12	$ 0.80	$ 1.09	$ 1.03	$ 0.60	$ 3.09	$ 3.52	$ 3.23
Diluted (dollars per share)	$ 0.31	$ 0.71	$ 0.92	$ 1.11	$ 0.79	$ 1.08	$ 1.01	$ 0.59	$ 3.05	$ 3.48	$ 3.18