Annual report pursuant to Section 13 and 15(d)

Business Segment Information - Segment Information (Details)

v3.20.4
Business Segment Information - Segment Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Segment Reporting Information [Line Items]      
Revenues $ 1,032,275 $ 866,933 $ 787,138
Interest income 250 524 282
Interest expense 12,891 12,622 15,344
Depreciation and intangible asset amortization 40,137 37,709 29,148
Income (loss) before taxes, excluding unallocated corporate activity 96,616 70,742 72,805
U.S. Regions      
Segment Reporting Information [Line Items]      
Revenues 400,526 365,060 334,344
U.S. Federal      
Segment Reporting Information [Line Items]      
Revenues 377,882 287,426 246,309
Canada      
Segment Reporting Information [Line Items]      
Revenues 47,797 37,910 38,982
Non-Solar DG      
Segment Reporting Information [Line Items]      
Revenues 106,418 84,683 82,655
All Other      
Segment Reporting Information [Line Items]      
Revenues 99,652 91,854 84,848
Operating Segments | U.S. Regions      
Segment Reporting Information [Line Items]      
Revenues 400,526 365,060 334,344
Interest income 136 166 9
Interest expense 5,783 5,858 6,188
Depreciation and intangible asset amortization 12,234 9,934 5,578
Income (loss) before taxes, excluding unallocated corporate activity 27,565 15,925 20,543
Operating Segments | U.S. Federal      
Segment Reporting Information [Line Items]      
Revenues 377,882 287,426 246,309
Interest income 77 208 126
Interest expense 1,771 831 1,045
Depreciation and intangible asset amortization 3,945 3,427 2,772
Income (loss) before taxes, excluding unallocated corporate activity 44,560 40,553 36,332
Operating Segments | Canada      
Segment Reporting Information [Line Items]      
Revenues 47,797 37,910 38,982
Interest income 0 0 0
Interest expense 852 691 1,917
Depreciation and intangible asset amortization 1,580 1,386 1,155
Income (loss) before taxes, excluding unallocated corporate activity 2,560 1,771 (2,746)
Operating Segments | Non-Solar DG      
Segment Reporting Information [Line Items]      
Revenues 106,418 84,683 82,655
Interest income 16 82 147
Interest expense 4,369 5,242 6,172
Depreciation and intangible asset amortization 20,717 21,359 18,101
Income (loss) before taxes, excluding unallocated corporate activity 13,040 3,813 13,412
Operating Segments | All Other      
Segment Reporting Information [Line Items]      
Revenues 99,652 91,854 84,848
Interest income 21 68 0
Interest expense 116 0 22
Depreciation and intangible asset amortization 1,661 1,603 1,542
Income (loss) before taxes, excluding unallocated corporate activity 8,891 8,680 5,264
Consolidation, Eliminations      
Segment Reporting Information [Line Items]      
Unallocated corporate activity $ (40,188) $ (34,189) $ (30,415)