Fair Value Measurements - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets:
Total	$ 3,010	$ 2,879
Level 1
Assets:
Total
Level 2
Assets:
Total	3,010	2,879
Level 3
Assets:
Total
Corporate bonds and notes
Assets:
Total	1,440	1,338
Corporate bonds and notes | Level 1
Assets:
Total
Corporate bonds and notes | Level 2
Assets:
Total	1,440	1,338
Corporate bonds and notes | Level 3
Assets:
Total
Municipal bonds
Assets:
Total	1,570	1,541
Municipal bonds | Level 1
Assets:
Total
Municipal bonds | Level 2
Assets:
Total	1,570	1,541
Municipal bonds | Level 3
Assets:
Total