Equity and Equity Compensation Plans - Compensation Costs for PSU's (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense	$ 13,743	$ 7,205	$ 26,327	$ 14,416
Performance Restricted Stock Units
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense			2,621	(158)
Performance Restricted Stock Units | Current Period
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense			2,621	336
Performance Restricted Stock Units | Prior Periods
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total expense			$ 0	$ (494)