Stockholders' Equity - Stock Options by Exercise Price (Details)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options Outstanding, Number Outstanding	405,000
Options Exercisable, Number Exercisable	280,000
$33.02
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options Outstanding, Number Outstanding	30,000
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 2 months 12 days
Options Outstanding, Weighted-Average Exercise Price | $ / shares	$ 33.02
Options Exercisable, Number Exercisable	30,000
Options Exercisable, Weighted-Average Exercise Price | $ / shares	$ 33.02
$67.33
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options Outstanding, Number Outstanding	375,000
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	7 years 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price | $ / shares	$ 67.33
Options Exercisable, Number Exercisable	250,000
Options Exercisable, Weighted-Average Exercise Price | $ / shares	$ 67.33