Share-Based Compensation - Stock Option Activity under Stock Option Plans (Details) - Jun. 30, 2015 - USD ($)	Total
Number of Shares
Beginning balance (in shares)	737,931
Granted (in shares)
Exercised (in shares)	(46,266)
Cancelled (in shares)	(100)
Ending balance (in shares)	691,565
Vested and Expected to Vest (in shares)	691,565
Exercisable (in shares)	691,565
Weighted-Average Exercise Price
Beginning balance (in dollars per share)	$ 20.99
Granted (in dollars per share)
Exercised (in dollars per share)	$ 15.28
Cancelled (in dollars per share)	28.25
Ending balance (in dollars per share)	21.37
Vested and Expected to Vest (in dollars per share)	21.37
Exercisable (in dollars per share)	$ 21.37
Weighted Average Remaining Contractual Term
Outstanding	2 years 7 months 20 days
Vested and Expected to Vest	2 years 7 months 6 days
Exercisable	2 years 7 months 20 days
Aggregate Intrinsic Value
Outstanding	$ 2,942,311
Vested and Expected to Vest	2,942,311
Exercisable	$ 2,942,311