Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Statement Of Partners Capital [Abstract]
Net income	$ 352,610	$ 348,927
Other comprehensive income, net of tax and reclassification adjustments:
Net unrealized gains (losses) on investment securities	(100,684)	(1,356)
Cash flow hedges adjustments	(10,442)	(23)
Foreign currency translation adjustment	1,290	476
Defined benefit plans liability adjustments	7,260	3,972
Total other comprehensive income (loss)	(102,576)	3,069
Total comprehensive income	$ 250,034	$ 351,996

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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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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