Share-Based Compensation Plans	6 Months Ended
Jun. 30, 2011
Share-Based Compensation Plans [Abstract]
SHARE-BASED COMPENSATION PLANS	NOTE 8. SHARE-BASED COMPENSATION PLANS In May 2011, UniSource Energy shareholders approved the UniSource Energy 2011 Omnibus Stock and Incentive Plan (2011 Plan), a new share-based compensation plan. The total number of shares which may be awarded under the 2011 Plan cannot exceed 1.2 million shares. The 2011 Plan supersedes all prior equity compensation plans (Prior Plans). The Prior Plans, however, shall remain in effect until all stock options and other awards granted under the Prior Plans have been exercised, forfeited, canceled, expired or terminated. RESTRICTED STOCK UNITS AND PERFORMANCE SHARES Restricted Stock Units In May 2011, the Compensation Committee of the UniSource Energy Board of Directors granted 14,655 restricted stock units to non-employee directors at a grant date fair value of $37.53 per share. The restricted stock units vest in one year or immediately upon death, disability, or retirement. Compensation expense equal to the fair market value on the grant date is recognized over the vesting period. Fully vested but undistributed stock unit awards accrue dividend equivalent stock units based on the fair market value of common shares on the date the dividend is paid. In the January following the year the person is no longer a director, common stock shares will be issued for the vested stock units. Performance Shares In March 2011, the Compensation Committee granted 80,440 performance share awards to officers. Half of the performance share awards had a grant date fair value, based on a Monte Carlo simulation, of $33.73 per share. Those awards will be paid out in shares of UniSource Energy Common Stock based on a comparison of UniSource Energy’s cumulative Total Shareholder Return to that of the Edison Electric Institute Index during the performance period of January 1, 2011 through December 31, 2013. The remaining half had a grant date fair value of $36.58 per share and will be paid out in shares of UniSource Energy Common Stock based on cumulative net income for the three-year period ended December 31, 2013. The performance shares vest based on the achievement of goals by the end of the performance period; any unearned awards are forfeited. Performance shares are eligible for dividend equivalents during the performance period. SHARE-BASED COMPENSATION EXPENSE UniSource Energy and TEP recorded share-based compensation expense of less than $1 million for the three months ended June 30, 2011 and 2010. For the six months ended June 30, 2011, UniSource Energy and TEP recorded share-based compensation expense of $2 million and $1 million, respectively, and $1 million and $1 million, respectively, for the six months ended June 30, 2010. At June 30, 2011, the total unrecognized compensation cost related to non-vested share-based compensation was $4 million, which will be recorded as compensation expense over the remaining vesting periods through December 2013. The total number of shares awarded but not yet issued, including target performance based shares, under the share-based compensation plans at June 30, 2011, was 1 million.

NOTE 8. SHARE-BASED COMPENSATION PLANS

In May 2011, UniSource Energy shareholders approved the UniSource Energy 2011 Omnibus Stock and Incentive Plan (2011 Plan), a new share-based compensation plan. The total number of shares which may be awarded under the 2011 Plan cannot exceed 1.2 million shares. The 2011 Plan supersedes all prior equity compensation plans (Prior Plans). The Prior Plans, however, shall remain in effect until all stock options and other awards granted under the Prior Plans have been exercised, forfeited, canceled, expired or terminated.

RESTRICTED STOCK UNITS AND PERFORMANCE SHARES

Restricted Stock Units

In May 2011, the Compensation Committee of the UniSource Energy Board of Directors granted 14,655 restricted stock units to non-employee directors at a grant date fair value of $37.53 per share. The restricted stock units vest in one year or immediately upon death, disability, or retirement. Compensation expense equal to the fair market value on the grant date is recognized over the vesting period. Fully vested but undistributed stock unit awards accrue dividend equivalent stock units based on the fair market value of common shares on the date the dividend is paid. In the January following the year the person is no longer a director, common stock shares will be issued for the vested stock units.

Performance Shares

In March 2011, the Compensation Committee granted 80,440 performance share awards to officers. Half of the performance share awards had a grant date fair value, based on a Monte Carlo simulation, of $33.73 per share. Those awards will be paid out in shares of UniSource Energy Common Stock based on a comparison of UniSource Energy’s cumulative Total Shareholder Return to that of the Edison Electric Institute Index during the performance period of January 1, 2011 through December 31, 2013. The remaining half had a grant date fair value of $36.58 per share and will be paid out in shares of UniSource Energy Common Stock based on cumulative net income for the three-year period ended December 31, 2013. The performance shares vest based on the achievement of goals by the end of the performance period; any unearned awards are forfeited. Performance shares are eligible for dividend equivalents during the performance period.

SHARE-BASED COMPENSATION EXPENSE

UniSource Energy and TEP recorded share-based compensation expense of less than $1 million for the three months ended June 30, 2011 and 2010. For the six months ended June 30, 2011, UniSource Energy and TEP recorded share-based compensation expense of $2 million and $1 million, respectively, and $1 million and $1 million, respectively, for the six months ended June 30, 2010.

At June 30, 2011, the total unrecognized compensation cost related to non-vested share-based compensation was $4 million, which will be recorded as compensation expense over the remaining vesting periods through December 2013. The total number of shares awarded but not yet issued, including target performance based shares, under the share-based compensation plans at June 30, 2011, was 1 million.