v3.6.0.2
Capital Structure
 12 Months Ended
Dec. 31, 2016
Capital Structure [Abstract]  
Capital Structure
Capital Structure
Common Stock
Our authorized common stock consists of 1.4 billion shares of Calpine Corporation common stock. Common stock issued as of December 31, 2016 and 2015, was 359,627,113 shares and 356,755,747 shares, respectively, at a par value of $0.001 per share. Common stock outstanding as of December 31, 2016 and 2015, was 359,061,764 shares and 356,662,004 shares, respectively. The table below summarizes our common stock activity for the years ended December 31, 2016, 2015 and 2014.
 
Shares
Issued
 
Shares
Held in
Treasury
 
Shares
Outstanding
Balance, December 31, 2013
497,841,056

 
(68,802,068
)
 
429,038,988

Shares issued under Calpine Equity Incentive Plans
4,445,966

 
(1,879,167
)
 
2,566,799

Share repurchase program
—

 
(49,684,523
)
 
(49,684,523
)
Balance, December 31, 2014
502,287,022

 
(120,365,758
)
 
381,921,264

Shares issued under Calpine Equity Incentive Plans
2,431,236

 
(1,089,328
)
 
1,341,908

Share repurchase program
—

 
(26,601,168
)
 
(26,601,168
)
Retirement of shares held in treasury
(147,962,511
)
 
147,962,511

 
—

Balance, December 31, 2015
356,755,747

 
(93,743
)
 
356,662,004

Shares issued under Calpine Equity Incentive Plans
2,871,366

 
(449,079
)
 
2,422,287

Share repurchase program
—

 
(22,527
)
 
(22,527
)
Balance, December 31, 2016
359,627,113

 
(565,349
)
 
359,061,764


Treasury Stock
As of December 31, 2016 and 2015, we had treasury stock of 565,349 shares and 93,743 shares, respectively, with a cost of $7 million and $1 million, respectively. Our treasury stock consists of shares repurchased as well as our common stock withheld to satisfy federal, state and local income tax withholding requirements for vested employee restricted stock awards and net share employee stock options exercises under the Equity Plan. All treasury stock is held at cost.