Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Name:	us-gaap_StockRepurchasedDuringPeriodShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Share Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Aug. 01, 2018
Share repurchase program [Abstract]
Stock repurchase program, authorized amount			$ 250.0
August 1, 2018 Program [Member]
Share repurchase program [Abstract]
Stock repurchased (in shares)	0	1,203,178
Weighted average price (in dollars per share)		$ 24.31
Stock repurchased aggregate value		$ 29.2