Subsequent Event (Details) (Subsequent Event, USD $)	0 Months Ended
Aug. 14, 2013
Subsequent Event
Declaration date	Aug. 14, 2013
Payment date	Sep. 27, 2013
Record date	Sep. 06, 2013
Common Stock
Subsequent Event
Dividend amount (in dollars per share)	$ 0.125
Class B Common Stock
Subsequent Event
Dividend amount (in dollars per share)	$ 0.125

Date the declared dividend will be paid, in CCYY-MM-DD format.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

+ Details

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- Definition

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

+ References

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- Definition

Date the dividend to be paid was declared, in CCYY-MM-DD format.

+ References

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- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

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