Changes in Accumulated Other Comprehensive Income (Loss) By Component (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 1,366,217	$ 1,117,086
Unrealized gains (losses) arising during period, before tax	(78,858)	12,715
Income tax effect	20,503	(3,306)
Other comprehensive income (loss) before reclassifications	(58,355)	9,409
Reclassification adjustments for (gains) losses included in net income, before tax	1,063	2,360
Income tax effect	(276)	(614)
Amounts reclassified from accumulated other comprehensive income (loss) to net income	787	1,746
Other comprehensive income (loss), net of income tax effect	(57,568)	11,155
Ending balance	1,377,406	1,188,721
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(4,980)	(5,764)
Other comprehensive income (loss), net of income tax effect	(57,568)	11,155
Ending balance	(62,548)	5,391
Unrealized Gains (Losses) on Available for Sale Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(4,980)	23,312
Unrealized gains (losses) arising during period, before tax	(78,858)	400
Income tax effect	20,503	(104)
Other comprehensive income (loss) before reclassifications	(58,355)	296
Reclassification adjustments for (gains) losses included in net income, before tax	1,063	(23,566)
Income tax effect	(276)	6,127
Amounts reclassified from accumulated other comprehensive income (loss) to net income	787	(17,439)
Other comprehensive income (loss), net of income tax effect	(57,568)	(17,143)
Ending balance	(62,548)	6,169
Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	0	(29,076)
Unrealized gains (losses) arising during period, before tax	0	12,315
Income tax effect	0	(3,202)
Other comprehensive income (loss) before reclassifications	0	9,113
Reclassification adjustments for (gains) losses included in net income, before tax	0	25,926
Income tax effect	0	(6,741)
Amounts reclassified from accumulated other comprehensive income (loss) to net income	0	19,185
Other comprehensive income (loss), net of income tax effect	0	28,298
Ending balance	$ 0	$ (778)

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