Stock-Based Compensation (Details) (2013 Plan, Restricted Stock Units, USD $)	0 Months Ended	3 Months Ended	6 Months Ended
	May 03, 2013	Jun. 30, 2013	Jun. 30, 2013 item
2013 Plan | Restricted Stock Units
Stock-based compensation
Shares granted	100,000
Number of equal installments to vest units over the service period from 2014 through 2017			4
Number of shares of common stock issued for each unit when vested		1	1
Grant date fair value (in dollars per unit)		$ 21.98	$ 21.98
Compensation expense recognized		$ 91,000	$ 91,000
Unrecognized compensation expense		$ 2,100,000	$ 2,100,000
Period to recognize unrecognized compensation expense			3 years 9 months 18 days
Accrued dividend equivalent units			0