Summary of Changes in Accumulated Balances of AOCI Including Current Period Other Comprehensive Income (Loss) and Reclassifications Out of AOCI (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 2,967,940	$ 2,808,663
Other comprehensive income (loss) before   reclassifications	32,386	27,184
Less: gain (loss) reclassified from AOCI	15,853	(2,047)
Tax effect	(1,640)	(413)
Net current-period other comprehensive income (loss)	14,893	28,818
Ending Balance	3,122,381	2,967,940
Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	7,201	(20,232)
Other comprehensive income (loss) before   reclassifications	25,266	25,386
Less: gain (loss) reclassified from AOCI	15,853	(2,047)
Tax effect	0	0
Net current-period other comprehensive income (loss)	9,413	27,433
Ending Balance	16,614	7,201
Unrealized Gains (Losses) on Cash Flow Hedges | Previously Reported
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(20,232)
Unrealized Gains (Losses) on Cash Flow Hedges | ASU 2018-02 | Restatement Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		0
Unrealized Gains (Losses) on Available-for-Sale Debt Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(1,917)	(3,308)
Other comprehensive income (loss) before   reclassifications	7,122	1,804
Less: gain (loss) reclassified from AOCI	0	0
Tax effect	(1,640)	(413)
Net current-period other comprehensive income (loss)	5,482	1,391
Ending Balance	3,565	(1,917)
Unrealized Gains (Losses) on Available-for-Sale Debt Securities | Previously Reported
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(2,722)
Unrealized Gains (Losses) on Available-for-Sale Debt Securities | ASU 2018-02 | Restatement Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(586)
Accumulated Gain Loss from Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(13)	(7)
Other comprehensive income (loss) before   reclassifications	(2)	(6)
Less: gain (loss) reclassified from AOCI	0	0
Tax effect	0	0
Net current-period other comprehensive income (loss)	(2)	(6)
Ending Balance	(15)	(13)
Accumulated Gain Loss from Other | Previously Reported
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(7)
Accumulated Gain Loss from Other | ASU 2018-02 | Restatement Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		0
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	5,271	(23,547)
Ending Balance	$ 20,164	5,271
Accumulated Other Comprehensive Income (Loss) | Previously Reported
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(22,961)
Accumulated Other Comprehensive Income (Loss) | ASU 2018-02 | Restatement Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		$ (586)