Summary of Significant Accounting Policies - Common Shares Outstanding (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	4,235,533	4,217,596
Issuance of shares in acquisition (in shares)		11,145
Vesting of restricted stock unit awards (in shares)	10,290	7,604
Shares withheld to cover taxes upon vesting of restricted stock unit awards (in shares)	(2,107)	(883)
Other (in shares)		71
Ending balance (in shares)	4,243,716	4,235,533