Stock Compensation (Details) (USD $)	6 Months Ended	12 Months Ended	0 Months Ended		6 Months Ended	0 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jan. 02, 2014 2013 Plan	Jun. 25, 2013 2013 Plan	Jun. 30, 2014 2013 Plan	Jun. 25, 2013 2008 Incentive Stock Option and Restricted Stock Plan
Stock compensation
Shares reserved and approved for issuance				1,100,000
Shares reserved under previous plan and subsequently transferred to new plan				54,129		54,129
Percentage of increase in the number of shares reserved and available for issuance				2.50%
Increase in the number of shares of stock reserved and available for issuance			383,935
Expiration period					10 years
Period from cessation of employment within which options expire if not exercised					90 days
Number of Options
Outstanding at the beginning of period (in shares)	1,401,101
Granted (in shares)	251,500
Forfeited or expired (vested and unvested) (in shares)	(38,771)
Exercised (in shares)	(87,590)
Outstanding at the end of the period (in shares)	1,526,240	1,401,101
Weighted-Average Price Per Share
Outstanding at the beginning of period (in dollars per share)	$ 9.59
Granted (in dollars per share)	$ 14.67
Forfeited or expired (vested and unvested) (in dollars per share)	$ 6.17
Exercised (in dollars per share)	$ 1.62
Outstanding at the end of the period (in dollars per share)	$ 10.98	$ 9.59
Weighted-Average Remaining Contractual Term (Years)
Outstanding at the end of the period	8 years 8 months 8 days	8 years 11 months 12 days
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)	$ 8,150,000	$ 7,755,000
Information about the stock option plan
Number of Options, vested and expected to vest (in shares)	1,465,510
Number of Options, exercisable (in shares)	609,994
Weighted-Average Price Per Share, vested and expected to vest (in dollars per share)	$ 10.90
Weighted-Average Price Per Share, exercisable (in dollars per share)	$ 4.59
Weighted-Average Remaining Contractual Term, vested and expected to vest	8 years 8 months 1 day
Weighted-Average Remaining Contractual Term, exercisable	7 years 9 months 11 days
Aggregate Intrinsic Value, vested and expected to vest (in dollars)	7,928,000
Aggregate Intrinsic Value, exercisable (in dollars)	6,956,000
Additional disclosures
Unrecognized compensation cost (in dollars)	$ 8,400,000
Weighted-average period over which remaining unrecognized compensation cost will be recognized	3 years