Aggregate dividends paid during the period for each share of common stock outstanding.

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Aggregate dividends declared during the period for each share of common stock outstanding.

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- Definition

The cash outflow to reacquire common stock during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

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Amount of stock repurchase plan authorized.

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Amount remaining of a stock repurchase plan authorized.

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- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

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Stockholders' Equity (Details) - USD ($)	3 Months Ended
Stockholders' Equity (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016	Aug. 01, 2017
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Amount of stock repurchase authorization					$ 200,000,000
Treasury Stock, Shares, Acquired		500,000
Payments for Repurchase of Common Stock		$ 25,400,000		$ 0
Amount remaining under stock repurchase authorization		$ 174,600,000
Dividends, Common Stock [Abstract]
Cash dividends declared per common share (in dollars per share)		$ 0.125	$ 0.10	$ 0.10
Cash dividends paid per common share (in dollars per share)		$ 0.125	$ 0.1	$ 0.1
Subsequent Event [Member]
Dividends, Common Stock [Abstract]
Cash dividends declared per common share (in dollars per share)	$ 0.125