Equity Compensation Plans - Unrecognized Compensation Cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	$ 25,122
Equity grants	20,911
Equity grant forfeitures	(303)
Equity compensation expense	(13,402)
Unrecognized Compensation Cost at End of Period	32,328
Restricted Stock Awards
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized Compensation Cost at End of Period	2,000
Restricted Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized Compensation Cost at End of Period	4,000
Deferred Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized Compensation Cost at End of Period	18,000
Performance Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized Compensation Cost at End of Period	9,000
Incentive Plans | Restricted Stock Awards
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	3,498
Equity grants	0
Equity grant forfeitures	0
Equity compensation expense	(1,508)
Unrecognized Compensation Cost at End of Period	1,990
Incentive Plans | Restricted Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	74
Equity grants	4,233
Equity grant forfeitures	0
Equity compensation expense	(773)
Unrecognized Compensation Cost at End of Period	3,534
Incentive Plans | Deferred Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	14,489
Equity grants	11,230
Equity grant forfeitures	(303)
Equity compensation expense	(7,558)
Unrecognized Compensation Cost at End of Period	17,858
Incentive Plans | Performance Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	7,061
Equity grants	5,275
Equity grant forfeitures	0
Equity compensation expense	(3,390)
Unrecognized Compensation Cost at End of Period	8,946
Employee Stock Purchase Plan
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	0
Equity grants	173
Equity grant forfeitures	0
Equity compensation expense	(173)
Unrecognized Compensation Cost at End of Period	$ 0