Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Partners Capital [Abstract]
Net income	$ 349,984	$ 280,401	$ 984,543	$ 808,702
Other comprehensive income (loss), net of tax and reclassification adjustments:
Net unrealized gains (losses) on investment securities	(17,133)	48,332	127,331	1,053
Cash flow hedges adjustments	(23)	(24)	(70)	823
Foreign currency translation adjustment	(229)	(3)	(1,847)	(521)
Defined benefit plans liability adjustments	3,847	5,724	11,654	16,166
Total other comprehensive income (loss)	(13,538)	54,029	137,068	17,521
Total comprehensive income	$ 336,446	$ 334,430	$ 1,121,611	$ 826,223