Share-Based Compensation - Narrative (Details) - USD ($)	1 Months Ended				3 Months Ended		9 Months Ended
	Mar. 31, 2017	Feb. 28, 2017	Mar. 31, 2016	Feb. 29, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Dec. 31, 2016
2017 Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Useful Life of the plan							10 years
Common stock shares issuable									1,750,000
Shares available for grant					1,746,927		1,746,927
2007 Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Award vesting period							3 years
2007 Plan | Performance Unit Incentive Plan (“PUP”)
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Awards granted during the period							$ 3,500,000
Stock value payable							1,400,000
Liability awards recorded					$ 10,300,000		10,300,000			$ 7,600,000
Payments to employees	$ 3,700,000		$ 200,000
2007 Plan | Restricted Stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unamortized cost					3,100,000		$ 3,100,000
Recognition period of unrecognized cost							1 year 2 months 13 days
Repurchase of common stock for employee tax withholding obligations amount, shares							26,916	24,432
Repurchase of common stock for employee tax withholding obligations amount							$ 1,300,000	$ 700,000
2007 Plan | Restricted Stock Units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Payments to employees		$ 300,000		$ 200,000
Liabilities related to restricted stock					400,000		400,000			$ 400,000
2007 Plan | Stock Options
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unamortized cost					$ 0		$ 0
Exercised					0		0
Forfeited or expired					0		0
Exercisable					63,773		63,773			63,773
Outstanding					63,773		63,773			63,773
Weighted-average exercise price					$ 16.62		$ 16.62			$ 16.62
Restructuring Charges
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation before income tax benefit					$ 0	$ 0	$ 0	$ 200,000