Share-Based Compensation - Exercise Prices (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding at end of year (in shares)	1,362,024	1,517,704
Outstanding, remaining contractual term (in years)	5 years 7 months 6 days
Outstanding at end of year	$ 6.09
Options exercisable at end of year	1,217,486
Options exercisable (usd per share)	$ 6.33
$2.24—$4.48
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	2.24
Exercise price range, upper range limit	$ 4.48
Outstanding at end of year (in shares)	386,908
Outstanding, remaining contractual term (in years)	7 years 9 months 17 days
Outstanding at end of year	$ 4.13
Options exercisable at end of year	251,701
Options exercisable (usd per share)	$ 4.16
$4.49—$6.72
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	4.49
Exercise price range, upper range limit	$ 6.72
Outstanding at end of year (in shares)	220,487
Outstanding, remaining contractual term (in years)	5 years 8 months 16 days
Outstanding at end of year	$ 5.46
Options exercisable at end of year	211,156
Options exercisable (usd per share)	$ 5.48
$6.73—$8.96
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	6.73
Exercise price range, upper range limit	$ 8.96
Outstanding at end of year (in shares)	744,629
Outstanding, remaining contractual term (in years)	4 years 5 months 19 days
Outstanding at end of year	$ 7.25
Options exercisable at end of year	744,629
Options exercisable (usd per share)	$ 7.25
$8.97—$11.20
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	8.97
Exercise price range, upper range limit	$ 11.20
Outstanding at end of year (in shares)	10,000
Outstanding, remaining contractual term (in years)	1 month 17 days
Outstanding at end of year	$ 9.99
Options exercisable at end of year	10,000
Options exercisable (usd per share)	$ 9.99