Stock-Based Compensation - Non-Vested Restricted Stock Award Activity (Details) shares in Thousands	6 Months Ended
	Jun. 30, 2021 $ / shares shares
Shares
Non-vested at beginning of period (in shares) | shares	374
Granted (in shares) | shares	123
Vested (in shares) | shares	(177)
Forfeited (in shares) | shares	(7)
Non-vested at end of period (in shares) | shares	313
Weighted-Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share) | $ / shares	$ 34.53
Granted (in dollars per share) | $ / shares	59.43
Vested (in dollars per share) | $ / shares	35.41
Forfeited (in dollars per share) | $ / shares	38.08
Non-vested at end of period (in dollars per share) | $ / shares	$ 43.74