Audit Information	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP	KPMG LLP
Auditor Location	Des Moines, Iowa	Des Moines, Iowa
Auditor Firm ID	42	185

PCAOB issued Audit Firm Identifier

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 10-K
-Number 249
-Section 310

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 20-F
-Number 249
-Section 220
-Subsection f

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form 40-F
-Number 249
-Section 240
-Subsection f

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Data Type:	dei:nonemptySequenceNumberItemType
Balance Type:	na
Period Type:	duration