Number of shares that have been repurchased and retired during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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Name:	us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Subsequent Events (Details) - USD ($)	Oct. 26, 2018	Jun. 30, 2012
2012 Stock Repurchase Program
Subsequent Event [Line Items]
Stock repurchase program, authorized amount (up to)		$ 1,000,000
Subsequent Event \| 2018 Stock Repurchase Program
Subsequent Event [Line Items]
Stock repurchase program, authorized amount (up to)	$ 100,000,000
Subsequent Event \| 2012 Stock Repurchase Program
Subsequent Event [Line Items]
Aggregate shares repurchased under program	237,455