Stock Incentive Plans and Share-Based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	3 Months Ended
	Jan. 02, 2017	Aug. 27, 2015	Jun. 30, 2007	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares Annual Increase				889,259	874,709
Maximum Number of Shares Authorized per One Participant				333,314	1,552,344	274,596	837,635
Stock Options, Outstanding, Number				4,213,033	2,419,903	3,402,481	2,419,529
Stock options granted in period				847,000	160,000
Weighted Average Exercise Price				$ 9.90	$ 8.49	$ 9.02	$ 8.16
Options, Exercised in Period				19,989	159,626
Employee Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted in period				847,000	160,000
Stock options weighted-average grant date fair value				$ 5.89	$ 3.94
Share-based Compensation Expense				$ 1.0	$ 0.4
Weighted Average Remaining Contractual Term				8 years 1 month 6 days
Weighted Average Exercise Price				$ 9.90
Aggregate Intrinsic Value				$ 14.2
Options, Exercisable, Weighted Average Remaining Contractual Term				1 year 7 months 6 days
Options, Exercisable, Weighted Average Exercise Price				$ 4.34
Options, Exercisable, Aggregate Intrinsic Value				$ 3.5
Options, Exercised in Period				19,989	159,626
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value				$ 0.1	$ 0.7
Stock Options, Unrecognized Share-based Compensation Expense				$ 14.5
Share-based Compensation Expense Not yet Recognized, Weighted-average Period for Recognition				3 years 3 months 18 days
2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock Options Expiration Term		10 years
Number of Shares Authorized		2,250,000
Number of Shares Annual Increase	889,259	1,800,000
Plan Shares Annual Increase, Percentage		4.00%
Maximum Number of Shares Authorized per One Participant		2,000,000		333,314
Stock Options, Outstanding, Number				3,539,358
Stock Options, Vested, Number				720,021
2015 Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Expense				$ 0.4
Number of RSUs outstanding				141,296
Number of RSUs vested				0
Stock Option and Compensation Plan of 2007 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock Options Expiration Term			10 years
Number of Shares Authorized			1,250,000
Maximum Number of Shares Authorized per One Participant				0
Stock Options, Outstanding, Number				673,675
Stock Options, Vested, Number				391,040