Number of shares that have been repurchased and retired during the period.

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Name:	us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Shareholder's Equity - Share Repurchases (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Nov. 21, 2019	Mar. 26, 2019
Equity, Class of Treasury Stock [Line Items]
Authorized repurchase amount		$ 50,000,000	$ 50,000,000
Shares repurchased and canceled (in shares)	505,699
Aggregate purchase price	$ 16,900,000
U.K.
Equity, Class of Treasury Stock [Line Items]
Stamp taxes payable	$ 100,000