Equity and Equity Compensation Plans - Compensation Costs for PSU's (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense	$ 12,583	$ 7,211
Performance Restricted Stock Units
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense	1,099	(464)
Performance Restricted Stock Units | Current Period
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense	1,099	153
Performance Restricted Stock Units | Prior Periods
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense	$ 0	$ (617)