Share-Based Compensation	3 Months Ended
Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	Share-Based Compensation We have a shareholder approved incentive compensation plan (the "Plan"), that provides for compensation payable in shares of our common stock. The Plan is administered by our Corporate Governance and Compensation Committee of our Board of Directors, which has complete discretion in determining our employees, officers and outside directors who shall be eligible to participate in the Plan, as well as the type, amount, terms and conditions of each award, subject to the limitations of the Plan. The number of shares of our common stock that may be issued pursuant to the Plan may not exceed in the aggregate 1,000,000 shares. As of September 30, 2016, approximately 751,000 shares of common stock were available for issuance under the Plan, subject to the limitations imposed by our Corporate Governance Guidelines. Shares of common stock may be available from authorized but unissued shares, shares reacquired by us or shares that we purchase in the open market. Upon vesting, the plan allows for withholding a number of shares equal in fair value to the taxes required to satisfy statutory withholding requirements. Compensation expense for share-based compensation is recorded in operation and maintenance expense in the Condensed Consolidated Statements of Income (Loss) based on the fair value of the awards at the grant date and is amortized over the requisite service period. Fair value is the closing price of our common shares at the grant date. The grant date is the date at which our commitment to issue the share-based awards arises, which is generally when the award is approved and the terms of the awards are communicated to the employee or director. We initially recognize expense for our performance shares when it is probable that any stipulated performance criteria will be met. Forfeitures of awards are recognized as they occur. For the three months ended September 30, 2016 and 2015, share-based compensation expense was $264,000 and $246,000, respectively. To the extent the cumulative deduction for income tax purposes exceeds the cumulative compensation expense recognized for financial reporting purposes, the excess tax benefits can be utilized to offset tax deficiencies related to share-based compensation in subsequent periods. For the three months ended September 30, 2016 and 2015, immaterial differences between compensation expense for financial reporting purposes and income tax purposes were recognized. Stock Awards For the three months ended September 30, 2016, common stock was awarded to Delta's eight outside directors having a grant date fair value of $247,000 (9,600 shares). The recipients vested in the awards shortly after the awards were granted, but during the time between the vesting dates and the grant dates the shares awarded were not transferable by the holders. Once the shares were vested, the shares received under the stock awards were immediately transferable. Performance Shares For the three months ended September 30, 2016 and 2015, performance shares were awarded to the Company's executive officers having grant date fair values of $1,056,000 (41,000 shares) and $787,000 (39,000 shares), respectively. The performance shares vest only if the performance objectives of the awards are met, which are based on the Company's earnings per common share for the fiscal year in which the performance shares are awarded, before any cash bonuses or share-based compensation. Upon satisfaction of the performance objectives, unvested shares are issued to the recipients and vest in one-third increments each August 31 subsequent to achieving the performance objectives as long as the recipients are employees throughout each such service period. Unvested shares of executive officers while still employed by the Company will fully vest upon them attaining the age of sixty-seven. The recipients of the awards also become vested as a result of certain events such as death or disability of the holders or a change in control. The unvested shares have both dividend participation rights and voting rights during the remaining terms of the awards. Holders of performance shares may not sell, transfer or pledge their shares until the shares vest. As of September 30, 2016 and 2015, there were 4,000 and 30,300 unvested performance shares outstanding, respectively, for which the performance objectives have been satisfied. Our performance shares have graded vesting schedules, and each separate annual vesting tranche is treated as a separate award for expense recognition. Compensation expense is amortized over the vesting period of the individual awards based on the probable outcome of meeting the performance objectives. For the three months ended September 30, 2016 and 2015, compensation expense related to the performance shares was $17,000 and $77,000, respectively.

Share-Based Compensation

We have a shareholder approved incentive compensation plan (the "Plan"), that provides for compensation payable in shares of our common stock. The Plan is administered by our Corporate Governance and Compensation Committee of our Board of Directors, which has complete discretion in determining our employees, officers and outside directors who shall be eligible to participate in the Plan, as well as the type, amount, terms and conditions of each award, subject to the limitations of the Plan.

The number of shares of our common stock that may be issued pursuant to the Plan may not exceed in the aggregate 1,000,000 shares. As of September 30, 2016, approximately 751,000 shares of common stock were available for issuance under the Plan, subject to the limitations imposed by our Corporate Governance Guidelines. Shares of common stock may be available from authorized but unissued shares, shares reacquired by us or shares that we purchase in the open market. Upon vesting, the plan allows for withholding a number of shares equal in fair value to the taxes required to satisfy statutory withholding requirements.

Compensation expense for share-based compensation is recorded in operation and maintenance expense in the Condensed Consolidated Statements of Income (Loss) based on the fair value of the awards at the grant date and is amortized over the requisite service period. Fair value is the closing price of our common shares at the grant date. The grant date is the date at which our commitment to issue the share-based awards arises, which is generally when the award is approved and the terms of the awards are communicated to the employee or director. We initially recognize expense for our performance shares when it is probable that any stipulated performance criteria will be met. Forfeitures of awards are recognized as they occur. For the three months ended September 30, 2016 and 2015, share-based compensation expense was $264,000 and $246,000, respectively.

To the extent the cumulative deduction for income tax purposes exceeds the cumulative compensation expense recognized for financial reporting purposes, the excess tax benefits can be utilized to offset tax deficiencies related to share-based compensation in subsequent periods. For the three months ended September 30, 2016 and 2015, immaterial differences between compensation expense for financial reporting purposes and income tax purposes were recognized.

Stock Awards

For the three months ended September 30, 2016, common stock was awarded to Delta's eight outside directors having a grant date fair value of $247,000 (9,600 shares). The recipients vested in the awards shortly after the awards were granted, but during the time between the vesting dates and the grant dates the shares awarded were not transferable by the holders. Once the shares were vested, the shares received under the stock awards were immediately transferable.

Performance Shares

For the three months ended September 30, 2016 and 2015, performance shares were awarded to the Company's executive officers having grant date fair values of $1,056,000 (41,000 shares) and $787,000 (39,000 shares), respectively. The performance shares vest only if the performance objectives of the awards are met, which are based on the Company's earnings per common share for the fiscal year in which the performance shares are awarded, before any cash bonuses or share-based compensation. Upon satisfaction of the performance objectives, unvested shares are issued to the recipients and vest in one-third increments each August 31 subsequent to achieving the performance objectives as long as the recipients are employees throughout each such service period. Unvested shares of executive officers while still employed by the Company will fully vest upon them attaining the age of sixty-seven. The recipients of the awards also become vested as a result of certain events such as death or disability of the holders or a change in control. The unvested shares have both dividend participation rights and voting rights during the remaining terms of the awards. Holders of performance shares may not sell, transfer or pledge their shares until the shares vest. As of September 30, 2016 and 2015, there were 4,000 and 30,300 unvested performance shares outstanding, respectively, for which the performance objectives have been satisfied.

Our performance shares have graded vesting schedules, and each separate annual vesting tranche is treated as a separate award for expense recognition. Compensation expense is amortized over the vesting period of the individual awards based on the probable outcome of meeting the performance objectives. For the three months ended September 30, 2016 and 2015, compensation expense related to the performance shares was $17,000 and $77,000, respectively.