Equity Incentive Compensation Plans and Other Long-term Incentive Programs - Non-Cash Stock-Based Compensation Cost Related to Equity Awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Based Compensation [Line Items]
Non-cash stock based compensation	$ 8,622	$ 7,226	$ 8,289
Nonvested Common Stock
Stock Based Compensation [Line Items]
Non-cash stock based compensation	6,601	6,036	5,852
Nonvested Equity Common Stock Units
Stock Based Compensation [Line Items]
Non-cash stock based compensation	1,177	1,138	690
Nonvested Performance-Based Equity
Stock Based Compensation [Line Items]
Non-cash stock based compensation	0	0	558
Nonvested Performance Cash Units
Stock Based Compensation [Line Items]
Cash Unit Based Compensation Awards	$ 844	$ 52	$ 1,189