Three months ended
September 30,

Nine months ended
September 30,

2011

2010

2011

2010

(in thousands, except per common share results)

Net income available for common stockholders

$

444,760

$

393,221

$

1,220,223

$

992,065

Weighted average outstanding shares of common stock used to compute basic earnings per common share

164,121

167,574

166,138

168,082

Dilutive effect of:

Employee stock options

895

634

962

589

Restricted stock

1,564

1,374

1,458

1,293

Shares used to compute diluted earnings per common share

166,580

169,582

168,558

169,964

Basic earnings per common share

$

2.71

$

2.35

$

7.34

$

5.90

Diluted earnings per common share

$

2.67

$

2.32

$

7.24

$

5.84

Number of antidilutive stock options and restricted stock excluded from computation

168

3,256

1,017

4,355