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Acquisitions (Narrative) (Details) |  |  |  |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | ---
Dec. 11, 2020 USD ($) | Oct. 15, 2020 USD ($) | Feb. 13, 2020 USD ($) | Jan. 15, 2020 USD ($) | Mar. 31, 2021 USD ($) | Mar. 31, 2020 USD ($) | Dec. 31, 2020 USD ($) business
Business Acquisition [Line Items] |  |  |  |  |  |  |
Number of businesses acquired | business |  |  |  |  |  |  | 5
Goodwill |  |  |  |  | $ 523,446,000 |  | $ 514,279,000
Acquisition related costs |  |  |  |  | 900,000 | $ 1,300,000 |
Cost of sales |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Acquisition related costs |  |  |  |  | 0 | $ 0 |
Renewables |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Number of businesses acquired | business |  |  |  |  |  |  | 2
Goodwill |  |  |  |  | 201,489,000 |  | $ 192,527,000
Agtech |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Number of businesses acquired | business |  |  |  |  |  |  | 2
Goodwill |  |  |  |  | 84,827,000 |  | $ 84,622,000
Residential |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Number of businesses acquired | business |  |  |  |  |  |  | 1
Goodwill |  |  |  |  | $ 205,452,000 |  | $ 205,452,000
TerraSmart LLC |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Acquisition purchase price |  |  |  |  |  |  | 223,700,000
Goodwill |  |  |  |  |  |  | $ 153,690,000
Sunfig Corporation |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Acquisition purchase price | $ 3,800,000 |  |  |  |  |  |
Goodwill | $ 3,200,000 |  |  |  |  |  |
Architectural Mailboxes, LLC |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Acquisition purchase price |  | $ 26,900,000 |  |  |  |  |
Goodwill |  | $ 7,400,000 |  |  |  |  |
Delta Separations, LLC |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Acquisition purchase price |  |  | $ 47,100,000 |  |  |  |
Goodwill |  |  | $ 32,200,000 |  |  |  |
Thermo Energy Systems |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |
Acquisition purchase price |  |  |  | $ 7,300,000 |  |  |
Goodwill |  |  |  | $ 18,700,000 |  |  |

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