Stock-Based Compensation - Additional Information (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 28, 2017 shares	Sep. 30, 2017 USD ($) plan	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) plan $ / shares shares	Sep. 30, 2016 USD ($) $ / shares	May 31, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of compensation plans | plan		3		3
Fair value of stock options vested | $		$ 100,000	$ 100,000	$ 3,000,000	$ 3,500,000
Allocated share-based compensation expense | $		1,600,000	1,400,000	4,800,000	4,100,000
Unrecognized stock-based compensation expense | $		11,000,000		$ 11,000,000
Weighted average, expected recognition period				2 years
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				3 years
Number of restricted stock units vested (in shares)				21,101
Number of restricted stock units unvested (in shares)				604
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				3 years
Performance Based Employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options vested (in shares)	9,616
Number of stock options unvested (in shares)	19,362
Performance Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock units vested (in shares)	300
Number of restricted stock units unvested (in shares)	604
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options unvested (in shares)				19,362
Total intrinsic value of stock options exercised (less than) | $		$ 100,000	$ 100,000	$ 100,000	$ 1,700,000
Employee Stock Option | Black-Scholes Option Valuation Model
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option weighted average grant date fair value (in dollars per share) | $ / shares				$ 14.51	$ 12.42
March 2017 | Year One | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2017 | Year One | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2017 | Year Two | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2017 | Year Two | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2017 | Year Three | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2017 | Year Three | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2016 | Year One | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2016 | Year One | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2016 | Year Two | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2016 | Year Two | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2016 | Year Three | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
March 2016 | Year Three | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
2015 | Year One | Performance Based Employee Stock Options | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
2015 | Year One | Performance Based Restricted Stock Units | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
2015 | Year Two | Performance Based Employee Stock Options | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
2015 | Year Two | Performance Based Restricted Stock Units | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
2015 | Year Three | Performance Based Employee Stock Options | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
2015 | Year Three | Performance Based Restricted Stock Units | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting installment (as a percent)				33.33%
Two Thousand Fourteen Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards authorized to grant (in shares)						1,974,543
Director S Plan Per Director | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term for value of shares to be granted upon election | $				$ 100,000
Vesting period (in years)				3 years
Director S Plan Per Director | Restricted Stock | Lead Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term for value of shares to be granted upon election | $				$ 40,000