Note 14 - Summarized Quarterly Data for Fiscal 2016 and 2015 (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2016 |
Jun. 30, 2015 |
Jun. 30, 2014 |
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| Operating revenues | $ 264,262 | $ 259,574 | $ 275,399 | $ 266,121 | $ 253,267 | $ 231,702 | $ 222,371 | $ 193,416 | $ 1,065,356 | $ 900,756 | $ 759,311 |
| Operating expenses | 258,838 | 248,043 | 261,320 | 244,949 | 231,846 | 216,374 | 206,802 | 179,948 | 1,013,150 | 834,971 | 719,877 |
| Operating income | 5,424 | 11,531 | 14,079 | 21,172 | 21,421 | 15,328 | 15,569 | 13,468 | 52,206 | 65,785 | 39,434 |
| Other expense, net | 3,135 | 3,632 | 3,779 | 3,252 | 2,797 | 2,066 | 1,969 | 1,092 | (257) | (154) | 15,996 |
| Income before taxes | 2,289 | 7,899 | 10,300 | 17,920 | 18,624 | 13,262 | 13,600 | 12,376 | |||
| Income tax expense | 666 | 2,660 | 3,685 | 6,553 | 6,589 | 4,670 | 5,057 | 4,329 | 13,564 | 20,645 | 19,690 |
| Net income | $ 1,623 | $ 5,239 | $ 6,615 | $ 11,367 | $ 12,035 | $ 8,592 | $ 8,543 | $ 8,047 | $ 24,844 | $ 37,217 | $ 30,681 |
| Basic income per share (in dollars per share) | $ 0.06 | $ 0.19 | $ 0.24 | $ 0.41 | $ 0.48 | $ 0.37 | $ 0.37 | $ 0.35 | $ 0.90 | $ 1.56 | $ 1.33 |
| Diluted income per share (in dollars per share) | $ 0.06 | $ 0.19 | $ 0.24 | $ 0.41 | $ 0.47 | $ 0.36 | $ 0.36 | $ 0.34 | $ 0.88 | $ 1.52 | $ 1.29 |
| X | ||||||||||
- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense. No definition available.
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- Definition The net result for the period of deducting operating expenses from operating revenues. No definition available.
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- Definition Amount of income (expense) related to nonoperating activities, classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Income before income taxes for oil and gas producing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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