| **Industry Segments Data (Reconciliation of reportable segment revenues) (Details) (USD $)In Thousands, unless otherwise specified** | 3 Months Ended | 12 Months Ended |
|--------------------------------------------------------------------------------------------------------------------------------------|----------------|-----------------|
||
| **Reconciliation from Segment Totals to Consolidated [Abstract]**                                                                    |           |            |   |   |   |   |   |   |   |   |   |
| Reportable Segment Revenues                                                                                                          |           |            |   |   |   |   |   |   | $ 716,446 | $ 685,698 | $ 656,868 |
| Less intersegment revenues eliminated in consolidation                                                                               |           |            |   |   |   |   |   |   | 6,265 | 6,317 | 5,618 |
| External revenues                                                                                                                    | $ 183,676      | $ 178,494       | $ 176,104 | $ 171,907 | $ 168,812 | $ 177,703 | $ 168,089 | $ 164,777 | $ 710,181 | $ 679,381 | $ 651,250 |

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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.
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| - Definition
Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of total revenue for the reportable segments, including revenue from external customers, transactions with other operating segments of the same entity, and (gross) interest revenue. All considered to be "operating revenue" for purposes of the taxonomy.
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