Stockholders' Equity - Summary of activity under stock-based incentive plans (Details) - Stock incentive plan - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Summary of the activity under the incentive plans
Share-based awards, beginning of period (in shares)	1,786,371	1,724,761	1,766,061	1,754,066
Granted (in shares)	37,978	39,493	203,701	78,837
Vested (in shares)	(46,041)	(24,996)	(191,454)	(93,645)
Share-based awards, end of period (in shares)	1,778,308	1,739,258	1,778,308	1,739,258
Restricted stock
Summary of the activity under the incentive plans
Shares withheld to pay estimated withholding taxes (in shares)			51,972	23,563