Subsequent Event (Details) - Common Stock - USD ($) $ / shares in Units, $ in Millions	Feb. 12, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 84.0
Subsequent Event
Subsequent Event [Line Items]
Dividends Payable, Amount Per Share	$ 0.06
Dividends Payable, Date to be Paid	Mar. 21, 2018
Dividends Payable, Date of Record	Mar. 01, 2018
Stock Repurchase Program, Authorized Amount	$ 100.0

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=98513485&loc=d3e4304-108586

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

+ References

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- Definition

Amount of stock repurchase plan authorized.

+ References

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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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