Stockholders' Equity - Range Of Exercise Prices (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($) $ / shares shares
2009 Stock Option Plan
Outstanding at ending of the year (in shares) | shares	235,074
Weighted Avg. Exercise Price (in dollars per share)	$ 35.85
Weighted Avg. Remaining Contractual Life	6 years 4 months 24 days
Total Intrinsic Value | $	$ 8,050
Vested options
2009 Stock Option Plan
Outstanding at ending of the year (in shares) | shares	125,395
Weighted Avg. Exercise Price (in dollars per share)	$ 27.92
Weighted Avg. Remaining Contractual Life	4 years 8 months 12 days
Total Intrinsic Value | $	$ 5,289
$23.00-$28.00
2009 Stock Option Plan
Exercise prices, low end of range (in dollars per share)	$ 23.00
Exercise prices, high end of range (in dollars per share)	$ 28.00
Outstanding at ending of the year (in shares) | shares	96,124
Weighted Avg. Exercise Price (in dollars per share)	$ 26.24
Weighted Avg. Remaining Contractual Life	4 years 6 months
Total Intrinsic Value | $	$ 4,216
$28.00-$32.00
2009 Stock Option Plan
Exercise prices, low end of range (in dollars per share)	$ 28.00
Exercise prices, high end of range (in dollars per share)	$ 32.00
Outstanding at ending of the year (in shares) | shares	14,073
Weighted Avg. Exercise Price (in dollars per share)	$ 29.84
Weighted Avg. Remaining Contractual Life	3 years 9 months 18 days
Total Intrinsic Value | $	$ 567
$32.00 - $47.00
2009 Stock Option Plan
Exercise prices, low end of range (in dollars per share)	$ 32.00
Exercise prices, high end of range (in dollars per share)	$ 47.00
Outstanding at ending of the year (in shares) | shares	124,877
Weighted Avg. Exercise Price (in dollars per share)	$ 43.93
Weighted Avg. Remaining Contractual Life	8 years 2 months 12 days
Total Intrinsic Value | $	$ 3,267