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Debt and Credit Facilities (Narrative) (Details) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2022 | Dec. 31, 2021
Line of Credit Facility [Line Items] |  |
Debt borrowing capacity | $ 600,000 |
Borrowings outstanding | 426,250 | $ 427,500
Line of credit borrowings outstanding | 230,000 |
Stand-by letters of credit | $ 53,900 |
Wells Fargo Term Loan Mature May 14, 2024 |  |
Schedule of Capitalization, Long-Term Debt [Line Items] |  |
Term loan maturity | May 14, 2024 |
Term loan outstanding amount | $ 100,000 |
Term loan interest rate | 1.05% |
BMO Harris Bank N.A. Term Loan Mature May 14, 2024 |  |
Schedule of Capitalization, Long-Term Debt [Line Items] |  |
Term loan maturity | May 14, 2024 |
Term loan face amount | $ 100,000 |
Term loan outstanding amount | $ 96,300 |
Term loan interest rate | 1.28% |
Frequency of periodic payment | quarterly |
Periodic payment, principal | $ 1,250 |
Wells Fargo Bank, N.A. Line of Credit Facility, Mature May 14, 2024 |  |
Line of Credit Facility [Line Items] |  |
Debt borrowing capacity | $ 300,000 |
Committed credit facilities maturity | May 14, 2024 |
Interest rate swap facility, amount | $ 75,000 |
Line of credit borrowings outstanding | $ 75,000 |
Line of credit facility, interest rate | 0.99% |
Interest rate swap facility, fixed interest | 2.32% |
Interest rate swap facility, maturity date | May 14, 2024 |
Maximum limit for aggregate amount of letters of credit issued | $ 75,000 |
BMO Harris Bank N.A. Line of Credit Facility, Mature May 14, 2024 |  |
Line of Credit Facility [Line Items] |  |
Debt borrowing capacity | $ 300,000 | $ 200,000
Committed credit facilities maturity | May 14, 2024 |
Interest rate swap facility, amount | $ 75,000 |
Line of credit borrowings outstanding | $ 75,000 |
Line of credit facility, interest rate | 0.93% |
Interest rate swap facility, fixed interest | 2.36% |
Interest rate swap facility, maturity date | May 14, 2024 |
Debt instrument, description of variable rate basis | SOFR |
Debt instrument, basis spread on variable rate | 0.10% |
Additional Outstanding Debt Under Credit Facilities |  |
Line of Credit Facility [Line Items] |  |
Line of credit borrowings outstanding | $ 80,000 |
Line of credit facility, interest rate | 1.02% |
SOFR | Wells Fargo Debt Facilities |  |
Schedule of Capitalization, Long-Term Debt [Line Items] |  |
Debt instrument, description of variable rate basis | SOFR |
Debt instrument, basis spread on variable rate | 0.10% |
Term SOFR | Wells Fargo Debt Facilities |  |
Schedule of Capitalization, Long-Term Debt [Line Items] |  |
Debt instrument description of fixed rate basis | Term SOFR |
Debt instrument basis spread on fixed rate one month term | 0.10% |
Debt instrument basis spread on fixed rate three month term | 0.15% |
Debt instrument basis spread on fixed rate six month term | 0.25% |
Minimum | Wells Fargo Bank, N.A. Line of Credit Facility, Mature May 14, 2024 |  |
Line of Credit Facility [Line Items] |  |
Letter of credit fee on outstanding amount, percentage | 0.55% |
Unused capacity commitment fee, percentage | 0.11% |
Minimum | BMO Harris Bank N.A. Line of Credit Facility, Mature May 14, 2024 |  |
Line of Credit Facility [Line Items] |  |
Debt instrument, basis spread on variable rate | 0.70% |
Minimum | SOFR | Wells Fargo Debt Facilities |  |
Schedule of Capitalization, Long-Term Debt [Line Items] |  |
Debt instrument, basis spread on variable rate | 0.675% |
Minimum | Term SOFR | Wells Fargo Debt Facilities |  |
Schedule of Capitalization, Long-Term Debt [Line Items] |  |
Debt instrument, basis spread on variable rate | 0.675% |
Maximum | Wells Fargo Bank, N.A. Line of Credit Facility, Mature May 14, 2024 |  |
Line of Credit Facility [Line Items] |  |
Letter of credit fee on outstanding amount, percentage | 0.80% |
Unused capacity commitment fee, percentage | 0.15% |
Maximum | BMO Harris Bank N.A. Line of Credit Facility, Mature May 14, 2024 |  |
Line of Credit Facility [Line Items] |  |
Debt instrument, basis spread on variable rate | 1.50% |
Maximum | SOFR | Wells Fargo Debt Facilities |  |
Schedule of Capitalization, Long-Term Debt [Line Items] |  |
Debt instrument, basis spread on variable rate | 0.925% |
Maximum | Term SOFR | Wells Fargo Debt Facilities |  |
Schedule of Capitalization, Long-Term Debt [Line Items] |  |
Debt instrument, basis spread on variable rate | 0.925% |

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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910 + Details
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