Equity-Based Compensation Expense (Tables)

9 Months Ended

Sep. 30, 2013

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Black-Scholes Option-Pricing Model Assumptions

The fair value of the Options granted during the nine months ended September 30, 2013 was estimated on the grant date using the Black-Scholes option-pricing model based on the following assumptions:

Estimated average Option life (years)	5.23
Risk free interest rate (range)	0.42% - 2.10%
Expected volatility (range)	17.98% - 32.72%
Expected dividend rate	0.00%
Grant-date fair value per share of Options granted	$271.24