v2.4.0.8

Stockholders' Equity (Details 2) (Class A common stock, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Class A common stock
Common Stock Repurchase Program
Amount of shares authorized for repurchase	$ 500.0

X

- Details

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X

- Definition

Amount of a stock repurchase plan authorized by an entity's Board of Directors.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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