Intangible Assets, Net And Goodwill (Schedule Of Intangible Assets, Net) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	$ 1,059,860	$ 829,831
Exchange And Clearing Organization Membership Interests And Registrations [Member]
Intangible Assets [Line Items]
Indefinite lived intangibles	16,060
Customer And Other Relationships [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	528,184	416,304
Intangibles, accumulated amortization	90,377	70,823
Trademarks And Tradename [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	371,712	263,839
Intangibles, accumulated amortization	21,588	15,731
Supply Contracts [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	134,972	140,121
Intangibles, accumulated amortization	15,023	9,874
Licenses [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	8,226	8,520
Intangibles, accumulated amortization	3,802	3,508
Other Intangible Assets [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	706	1,047
Intangibles, accumulated amortization	$ 4,458	$ 4,467