Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Partners Capital [Abstract]
Net income	$ 473,260	$ 493,160	$ 956,002	$ 845,770
Other comprehensive income (loss), net of tax and reclassification adjustments:
Net unrealized gains (losses) on investment securities	69,853	(36,733)	154,444	(137,417)
Cash flow hedges adjustments	102,050	(2,569)	146,971	(13,011)
Foreign currency translation adjustment	(675)	(2,434)	(400)	(1,144)
Defined benefit plans liability adjustments	3,823	7,038	6,108	14,298
Total other comprehensive income (loss)	175,051	(34,698)	307,123	(137,274)
Total comprehensive income	$ 648,311	$ 458,462	$ 1,263,125	$ 708,496

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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