Fair Value Measurements (Supply Commitment) (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Supply Commitment [Line Items]
Outstanding financial letters of credit	$ 3,946
Less than one year [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	2,418
More than one year to five years [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	521
Over five years [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	1,007
Secured [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	3,632
Secured [Member] | Less than one year [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	2,126
Secured [Member] | More than one year to five years [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	499
Secured [Member] | Over five years [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	1,007
Secured by Collateral [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	1,590
Secured by Collateral [Member] | Less than one year [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	220
Secured by Collateral [Member] | More than one year to five years [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	363
Secured by Collateral [Member] | Over five years [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	1,007
Secured by Bank Lines of Credit [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	935
Secured by Bank Lines of Credit [Member] | Less than one year [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	799
Secured by Bank Lines of Credit [Member] | More than one year to five years [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	136
Secured by Other [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	1,107
Secured by Other [Member] | Less than one year [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	1,107
Unsecured [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	314
Unsecured [Member] | Less than one year [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	292
Unsecured [Member] | More than one year to five years [Member]
Supply Commitment [Line Items]
Outstanding financial letters of credit	$ 22