CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement Of Partners Capital [Abstract]
Net income	$ 229,017	$ 274,113
Other comprehensive income, net of tax and reclassification adjustments:
Net unrealized gains on investment securities	38,214	10,079
Foreign currency translation adjustment	(136)	(932)
Defined benefit plans liability adjustment	820	5,164
Total other comprehensive income	38,898	14,311
Total comprehensive income	$ 267,915	$ 288,424