Basis of Presentation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015 item	Mar. 31, 2014
Description of Business
Number of operating segments			3us-gaap_NumberOfOperatingSegments
Earnings per Share
Antidilutive shares associated with stock awards or stock awards or units		100,000
Computation of basic and diluted earnings per share
Net income for diluted earnings per share calculation	$ 13,228	$ 4,801	$ 42,718	$ 25,768
Weighted average shares outstanding for basic earnings per share calculation	19,801,000	19,936,000	19,810,000	19,956,000
Dilutive effect of stock awards (in shares)	728,000	612,000	705,000	629,000
Weighted average shares outstanding for diluted earnings per share calculation	20,529,000	20,548,000	20,515,000	20,585,000
Basic net income per share (in dollars per share)	$ 0.67us-gaap_EarningsPerShareBasic	$ 0.24us-gaap_EarningsPerShareBasic	$ 2.16us-gaap_EarningsPerShareBasic	$ 1.29us-gaap_EarningsPerShareBasic
Diluted net income per share (in dollars per share)	$ 0.64us-gaap_EarningsPerShareDiluted	$ 0.23us-gaap_EarningsPerShareDiluted	$ 2.08us-gaap_EarningsPerShareDiluted	$ 1.25us-gaap_EarningsPerShareDiluted

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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