Stockholders' Equity (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Nov. 30, 2019	Dec. 31, 2018
Stockholders' equity
Common stock, outstanding shares (in shares)	16,802,000				16,802,000		16,843,000
Shares purchased	$ 0	$ 3,600,000	$ 1,600,000	$ 300,000
Stock acquired (in shares)					3,612	1,851
Maximum
Stockholders' equity
Stock acquired					$ 200,000	$ 100,000
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	31,268
Shares purchased					$ 0	$ 1,900,000
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