Employee Stock Plans (Disclosure Continued) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) executive award $ / shares shares	Dec. 31, 2014 USD ($) award $ / shares shares	Dec. 31, 2013 USD ($) award $ / shares shares	Dec. 31, 2012 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted common stock (in shares) | shares	78,448	86,205	76,167
Stock-based compensation expense	$ 11,560	$ 10,384	$ 8,286
Restricted Stock Awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, granted (in dollars per share) | $ / shares	$ 10.83	$ 8.12	$ 9.19
Fair value of vested shares	$ 800	$ 700	$ 700
Aggregate intrinsic value outstanding	5,100	6,700
Unrecognized compensation costs	$ 500	$ 500
Weighted average period of recognizing share based compensation expenses	1 year 2 months 12 days	8 months 12 days
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, granted (in dollars per share) | $ / shares	$ 9.51	$ 9.22	$ 7.36
Fair value of vested shares	$ 6,000	$ 4,600	$ 1,500
Aggregate intrinsic value outstanding	$ 18,400	$ 21,000
Weighted average period of recognizing share based compensation expenses	2 years 5 months 27 days	2 years 8 months 15 days
Fair value of market based award		$ 2,100
Unrecognized compensation expense	$ 12,900	$ 11,300
Forfeited (in shares) | shares	484,021
Number of awards that began vesting in period | award	2
Award vesting period	3 years
2010 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares) | shares	2,605,034
2010 Equity Incentive Plan | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of market based award	$ 4,300
Issuance of restricted common stock (in shares) | shares	582,026
Forfeited (in shares) | shares	128,200
Grant date fair value of shares forfeited	$ 1,100
Modified Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executives seperated during period | executive	2
Stock-based compensation expense	$ 300
Expense reversed related to forfeiture of unvested options	$ 300
Number of awards modified | award		0	0
2010 Employee Stock Purchase Plan | Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares) | shares			1,000,000
Purchase price, percentage of fair value			85.00%
Shares reserved for future issuance (in shares) | shares	1,000,000
Shares issued (in shares) | shares	665,523
Shares available for future issuance (in shares) | shares	334,477
Chief Executive Officer | Restricted Stock Awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of market based award				$ 2,100
Expected life	3 years 9 months 18 days
Non-Employee | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted common stock (in shares) | shares		83,914