Stock Option Activity - Summary of Stock Option Activity (Table) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended
	Jun. 30, 2012	Sep. 30, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance, number of shares outstanding		11,302,228
Number of shares, stock options granted		561,780	452,900
Number of shares, options exercised		(98,794)
Number of shares, options forfeited		(74,386)
End balance, number of shares outstanding	11,302,228	11,690,828
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Beginning balance, weighted average exercise price per share, options outstanding		$ 10.36
Weighted average exercise price per share, options granted		$ 12.50
Weighted average exercise price per share, options exercised		$ 3.64
Weighted average exercise price per share, options forfeited		$ 15.96
End balance, weighted average exercise price per share, options outstanding	$ 10.36	$ 10.49
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Balance, weighted average remaining contractual term of options oustanding	6 years 6 months	6 years 5 months 12 days
Balance, aggregate intrinsic value of options oustanding	$ 66,062	$ 34,446
Number of shares options vested and expected to vest		11,265,255
Weighted average exercise price per share, options vested and expected to vest		$ 10.31
Weighted average remaining contractual term, options vested and expected to vest		6 years 4 months 2 days
Aggregate intrinsic value of options vested and expected to vest		34,418
Number of shares options vested and exercisable		7,880,282
Weighted average exercise price per share, options vested and exercisable		$ 8.62
Weighted average remaining contractual term, options vested and exercisable		5 years 4 months
Aggregate intrinsic value of options vested and exercisable		$ 32,648