Incentive Based Compensation (Details) - 6 months ended Jun. 30, 2015 - $ / shares		Total
Stock Options
Beginning year stock option awards		13,427,836
Granted stock option awards	[1]	724,082
Exercised stock option awards		(480,458)
Canceled stock option awards		(455,855)
End of period stock option awards		13,215,605
Beginning year weighted average exercise price		$ 29.68
Granted weighted average exercise price		29.06
Exercises weighted average exercise price		16.47
Canceled weighted average exercise price		34.48
End of period weighted average exercise price		29.97
Stock options weighted average grant date fair value		$ 6.84

[1] The weighted average grant date fair value of stock option awards granted was $6.84 per share.