Repurchases of common stock under stock repurchase program.

No definition available.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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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- Definition

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

+ References

+ Details

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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

Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

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- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

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Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions				3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 15, 2018	Aug. 30, 2018	May 15, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Feb. 25, 2016
Common stock dividends paid						$ 193,400,000	$ 178,200,000
Dividends declared per common share				$ 0.79	$ 0.63	$ 2.21	$ 1.89
Dividends declared date						Aug. 30, 2018
Dividends paid per common share (in dollars per share)		$ 0.79
Stock repurchase program, authorized amount									$ 200,000,000
Repurchases of common stock under stock repurchase program				0		0
Common stock repurchase authorization amount available				$ 193,000,000		$ 193,000,000
Annual Dividend [Member]
Dividends declared per common share			$ 3.16					$ 2.52
Subsequent Event
Common stock dividends paid	$ 74,700,000