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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net income	$ 31,163	$ 42,239	$ 39,806	$ 23,232	$ 24,883	$ 33,717	$ 33,179	$ 32,371	$ 136,440	$ 124,150	$ 26,027
Preferred stock dividends									42	42	42
Net income available to common equity									136,398	124,108	25,985
Dividends and undistributed earnings allocated to participating securities									(183)	(117)	(62)
Net income available to common shareholders									$ 136,215	$ 123,991	$ 25,923
Basic weighted-average shares outstanding									38,653	38,362	37,997
Stock options and other stock compensation									536	599	700
Diluted weighted-average shares outstanding									39,189	38,961	38,697
Antidilutive stock options									0	0	0
Earnings per share:
Basic (dollars per share)	$ 0.80	$ 1.09	$ 1.03	$ 0.60	$ 0.65	$ 0.88	$ 0.86	$ 0.85	$ 3.52	$ 3.23	$ 0.68
Diluted (dollars per share)	$ 0.79	$ 1.08	$ 1.01	$ 0.59	$ 0.64	$ 0.86	$ 0.85	$ 0.83	$ 3.48	$ 3.18	$ 0.67