Stockholders' Equity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Nov. 30, 2019	Dec. 31, 2018
Stockholders' equity
Common stock, outstanding shares (in shares)	16,791,000		16,843,000
Shares purchased	$ 3,600,000	$ 300,000
Stock acquired (in shares)	3,476
Maximum
Stockholders' equity
Stock acquired	$ 200,000
2020 Stock Purchase Plan
Stockholders' equity
Common stock purchased under the stock purchase plan (in shares)	59,577	0
Shares purchased	$ 3,600,000	$ 0
2020 Stock Purchase Plan | Maximum
Stockholders' equity
Authorized amount of repurchase under the stock purchase plan (up to)				$ 25,000,000
2019 Stock Purchase Plan
Stockholders' equity
Common stock purchased under the stock purchase plan (in shares)	0	4,285
Shares purchased	$ 0	$ 300,000
2019 Stock Purchase Plan | Maximum
Stockholders' equity
Authorized amount of repurchase under the stock purchase plan (up to)			$ 25,000,000
2018 Stock Purchase Plan | Maximum
Stockholders' equity
Authorized amount of repurchase under the stock purchase plan (up to)					$ 25,000,000