Accumulated Other Comprehensive Income - Summary of Changes in Accumulated Balances of AOCI Including Current Period Other Comprehensive Income (Loss) and Reclassifications Out of AOCI (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	[1]	$ 2,967,940	$ 2,808,663	$ 2,967,940	[2]	$ 2,808,663
Beginning Balance						(23,547)
Other comprehensive income (loss) before reclassifications		1,913	25,108	18,192		13,862
Less: gain (loss) reclassified from AOCI		3,512	(2,659)	4,478		(8,444)
Tax effect		(756)	(351)	(1,546)		112
Net current-period other comprehensive income (loss)		(2,355)	27,416	12,168		22,418
Ending Balance		2,960,954	2,885,104	2,960,954		2,885,104
ASU 2018-02
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Impact of change in accounting principle								$ (586)
Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		19,060	(23,673)	7,201		(20,232)
Beginning Balance						(20,232)
Other comprehensive income (loss) before reclassifications		(1,367)	23,582	11,458		14,356
Less: gain (loss) reclassified from AOCI		3,512	(2,659)	4,478		(8,444)
Tax effect		0	0	0		0
Net current-period other comprehensive income (loss)		(4,879)	26,241	6,980		22,800
Ending Balance		14,181	2,568	14,181		2,568
Unrealized Gains (Losses) on Cash Flow Hedges | ASU 2018-02
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Impact of change in accounting principle								0
Unrealized Gains (Losses) on Available for-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		748	(4,866)	(1,917)		(2,722)
Beginning Balance						(3,308)
Other comprehensive income (loss) before reclassifications		3,279	1,531	6,734		(490)
Less: gain (loss) reclassified from AOCI		0	0	0		0
Tax effect		(756)	(351)	(1,546)		112
Net current-period other comprehensive income (loss)		2,523	1,180	5,188		(378)
Ending Balance		3,271	(3,686)	3,271		(3,686)
Unrealized Gains (Losses) on Available for-Sale Debt Securities | ASU 2018-02
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Impact of change in accounting principle								(586)
Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(14)	(6)	(13)		(7)
Beginning Balance						(7)
Other comprehensive income (loss) before reclassifications		1	(5)	0		(4)
Less: gain (loss) reclassified from AOCI		0	0	0		0
Tax effect		0	0	0		0
Net current-period other comprehensive income (loss)		1	(5)	0		(4)
Ending Balance		(13)	(11)	(13)		(11)
Other | ASU 2018-02
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Impact of change in accounting principle								$ 0
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	[1]	19,794	(28,545)	5,271		(22,961)
Impact of change in accounting principle							$ (586)
Ending Balance		$ 17,439	$ (1,129)	$ 17,439		$ (1,129)

[1] The beginning balances for the six month periods were derived from the audited Consolidated Financial Statements included in Company’s Annual Report on Form 10-K for the year ended December 31, 2018, filed with the SEC on February 28, 2019.

[2] December 31, 2018 balances were derived from the audited Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, filed with the SEC on February 28, 2019.