Leases (Narrative) (Details)	3 Months Ended
Mar. 31, 2021
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract (years)	10 years
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract (years)	25 years
Office Space
Lessee, Lease, Description [Line Items]
Lease obligations, percent	99.00%

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant