Stockholder's Equity (Details 2) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Equity Incentive Plans
Shares available for issuance	1,355,547	1,355,547
Stock-Based Compensation
Stock-based compensation expense (in dollars)	$ 3,106,531	$ 3,106,531
Class A Common Stock
Equity Incentive Plans
Shares authorized for issuance	4,000,000	4,000,000
Stock Options
Equity Incentive Plans
Granted (in shares)		1,575,000
Stock-Based Compensation
Unrecognized compensation cost related to non-vested stock options (in dollars)	5,500,000	5,500,000
Weighted-average periods over which unrecognized compensation cost recognized		2 years
Estimated forfeitures (as a percent)	1.50%	1.50%
Valuation assumptions
Dividend yield (as a percent)		0.00%
Weighted average grant date fair value of options granted (in dollars per share)		$ 3.83
Number of shares
Granted (in shares)		1,575,000
Outstanding at the end of the period (in shares)	1,575,000	1,575,000
Vested at the end of the period (in shares)	275,000	275,000
Exercisable at the end of the period (in shares)	275,000	275,000
Weighted-average exercise price
Granted (in dollars per share)		$ 11.19
Outstanding at the end of the period (in dollars per share)	$ 11.19	$ 11.19
Vested at the end of the period (in dollars per share)	$ 10.20	$ 10.20
Exercisable at the end of the period (in dollars per share)	$ 10.20	$ 10.20
Weighted-average contractual term
Outstanding at the beginning of the period		10 years
Granted		10 years
Outstanding at the end of the period		10 years
Vested at the end of the period		10 years
Exercisable at the end of the period		10 years
Aggregate intrinsic value
Granted (in dollars)	4,375,000	4,375,000
Outstanding at the end of the period (in dollars)	4,375,000	4,375,000
Vested at the end of the period (in dollars)	962,500	962,500
Exercisable at the end of the period (in dollars)	962,500	962,500
Stock Options | Class A Common Stock
Equity Incentive Plans
Granted (in shares)		1,575,000
Number of shares
Granted (in shares)		1,575,000
Restricted Stock
Equity Incentive Plans
Granted (in shares)		1,135,002
Stock-Based Compensation
Unrecognized compensation cost related to non-vested restricted stock (in dollars)	8,000,000	8,000,000
Weighted-average periods over which unrecognized compensation cost recognized		1 year 3 months 18 days
Number of shares
Granted (in shares)		1,135,002
Vested (in shares)		(250,000)
Outstanding at the end of the period (in shares)	885,002	885,002
Weighted-average grant date fair value
Granted (in dollars per share)		$ 9.53
Vested (in dollars per share)		$ 8.12
Outstanding at the end of the period (in dollars per share)	$ 9.92	$ 9.92
Aggregate intrinsic value
Granted (in dollars)		4,814,250
Vested (in dollars)		(1,395,000)
Outstanding at the end of the period (in dollars)	$ 3,419,250	$ 3,419,250
Restricted Stock | Class A Common Stock
Equity Incentive Plans
Granted (in shares)		1,135,002
Number of shares
Granted (in shares)		1,135,002
Time-based restricted stock awards and option awards
Equity Incentive Plans
Number of equal annual installments for vesting of awards	3	3
Time-based option
Aggregate intrinsic value
Vesting period		3 years
Time-based option | Black-Scholes pricing model
Valuation assumptions
Volatility (as a percent)		32.50%
Weighted-average expected term		6 years
Time-based option | Black-Scholes pricing model | Maximum
Valuation assumptions
Risk-free interest rates (as a percent)		1.02%
Time-based option | Black-Scholes pricing model | Minimum
Valuation assumptions
Risk-free interest rates (as a percent)		0.93%
Time-based option | Monte Carlo simulation model
Valuation assumptions
Risk-free interest rates (as a percent)		1.78%
Volatility (as a percent)		32.50%
Time-based option | Monte Carlo simulation model | Maximum
Valuation assumptions
Weighted-average expected term		6 years
Time-based option | Monte Carlo simulation model | Minimum
Valuation assumptions
Weighted-average expected term		5 years 3 months 18 days
Time-based restricted stock
Aggregate intrinsic value
Vesting period		3 years
Event-based restricted stock awards and option awards | Class A Common Stock | Maximum
Equity Incentive Plans
Closing price per share to be attained for vesting of awards to begin (in dollars per share)		$ 15.00
Event-based restricted stock awards and option awards | Class A Common Stock | Minimum
Equity Incentive Plans
Closing price per share to be attained for vesting of awards to begin (in dollars per share)		$ 12.50
Number of trading days on which the closing price per share should attain the specified price per share for vesting of awards to begin	10	10
Event-based option
Aggregate intrinsic value
Unvested options	300,000	300,000
Event-based restricted stock
Aggregate intrinsic value
Unvested options	150,000	150,000
Event-based restricted stock | Monte Carlo simulation model
Valuation assumptions
Risk-free interest rates (as a percent)		1.78%
Volatility (as a percent)		32.50%
Event-based restricted stock | Monte Carlo simulation model | Maximum
Valuation assumptions
Weighted-average expected term		1 year 4 months 24 days
Event-based restricted stock | Monte Carlo simulation model | Minimum
Valuation assumptions
Weighted-average expected term		9 months 18 days