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Stock Repurchase (Details) (USD $)	9 Months Ended	0 Months Ended
	Sep. 30, 2014	Sep. 25, 2014 Share Repurchase Agreement with Capital Southwest Corporation and Capital Southwest Venture Corporation	Sep. 24, 2014 Share Repurchase Agreement with Capital Southwest Corporation and Capital Southwest Venture Corporation	Sep. 24, 2014 Share Repurchase Agreement with Capital Southwest Corporation and Capital Southwest Venture Corporation
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased owned by Capital Southwest				849,690
Purchase price per share			$ 40.255
Closing price of common stock				$ 41.50
Common Stock Issued and Outstanding [Roll Forward]
Balance (shares)	12,070,509
Exercise of stock options (shares)	23,231
Retirement of shares (shares)	(849,690)	(849,690)
Balance (shares)	11,244,050

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