Intangible Assets, Net And Goodwill (Schedule Of Intangible Assets, Net) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	$ 1,004,933	$ 1,020,529
Exchange And Clearing Organization Membership Interests And Registrations [Member]
Intangible Assets [Line Items]
Indefinite lived intangibles	14,752	14,916
Customer And Other Relationships [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	511,819	502,409
Intangibles, accumulated amortization	146,036	117,139
Trademarks And Tradename [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	353,229	364,779
Intangibles, accumulated amortization	42,966	30,213
Supply Contracts [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	122,128	129,833
Intangibles, accumulated amortization	27,867	20,162
Licenses [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)		7,928
Intangibles, accumulated amortization	110	4,100
Other Intangible Assets [Member]
Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	3,005	664
Intangibles, accumulated amortization	$ 4,598	$ 4,500