Share Repurchases (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2015
Comprehensive Income
Share repurchase program amount authorized				$ 10,000
Shares repurchased (in shares)		0	0
Shares paid for tax withholding for share-based compensation	5,622
Weighted average per share prices for shares used to pay tax withholding liability (in dollars per share)	$ 99.08