Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Partners' Capital [Abstract]
Net income	$ 280,401	$ 275,344	$ 808,702	$ 788,697
Other comprehensive income (loss), net of tax and reclassification adjustments:
Net unrealized gains (losses) on investment securities	48,332	(27,637)	1,053	75,229
Unrealized gains (losses) on cash flow hedges	(24)	613	823	(98)
Foreign currency translation adjustment	(3)	(1,817)	(521)	(1,504)
Defined benefit plans liability adjustment	5,724	1,000	16,166	2,999
Total other comprehensive income (loss)	54,029	(27,841)	17,521	76,626
Total comprehensive income	$ 334,430	$ 247,503	$ 826,223	$ 865,323