Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Partners' Capital [Abstract]
Net income	$ 1,079,667	$ 1,066,246	$ 1,138,480
Other comprehensive income, net of tax and reclassification adjustments:
Net unrealized gains (losses) on investment securities	(79,114)	93,275	(2,865)
Unrealized gains (losses) on cash flow hedges	796	(96)
Foreign currency translation adjustment	(925)	(2,607)	381
Defined benefit plans liability adjustments	8,610	(207,407)	178,589
Total other comprehensive income (loss)	(70,633)	(116,835)	176,105
Total comprehensive income	$ 1,009,034	$ 949,411	$ 1,314,585