Annual report pursuant to Section 13 and 15(d)

Business Segment Information - Segment Information (Details)

v3.19.3.a.u2
Business Segment Information - Segment Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Segment Reporting Information [Line Items]                      
Revenues $ 306,612 $ 212,026 $ 198,183 $ 150,112 $ 217,371 $ 205,375 $ 196,982 $ 167,410 $ 866,933 $ 787,138 $ 717,152
Interest income                 524 282 130
Interest expense                 12,622 15,344 9,082
Depreciation and intangible asset amortization                 37,709 29,148 23,915
Unallocated corporate activity                 (34,156) (30,415) (27,195)
Income (loss) before taxes, excluding unallocated corporate activity                 70,709 72,805 55,912
U.S. Regions                      
Segment Reporting Information [Line Items]                      
Revenues                 365,060 334,344  
U.S. Federal                      
Segment Reporting Information [Line Items]                      
Revenues                 287,426 246,309  
Non-Solar DG                      
Segment Reporting Information [Line Items]                      
Revenues                 84,683 82,655  
Operating Segments | U.S. Regions                      
Segment Reporting Information [Line Items]                      
Revenues                 365,060 334,344 290,196
Interest income                 166 9 2
Interest expense                 5,858 6,188 2,672
Depreciation and intangible asset amortization                 9,934 5,578 2,974
Income (loss) before taxes, excluding unallocated corporate activity                 15,925 20,543 13,865
Operating Segments | U.S. Federal                      
Segment Reporting Information [Line Items]                      
Revenues                 287,426 246,309 229,146
Interest income                 208 126 44
Interest expense                 831 1,045 1,056
Depreciation and intangible asset amortization                 3,427 2,772 2,623
Income (loss) before taxes, excluding unallocated corporate activity                 40,553 36,332 29,261
Operating Segments | Canada                      
Segment Reporting Information [Line Items]                      
Revenues                 37,910 38,982 43,803
Interest income                 0 0 1
Interest expense                 691 1,917 1,927
Depreciation and intangible asset amortization                 1,386 1,155 1,178
Income (loss) before taxes, excluding unallocated corporate activity                 1,771 (2,746) 1,751
Operating Segments | Non-Solar DG                      
Segment Reporting Information [Line Items]                      
Revenues                 84,683 82,655 79,220
Interest income                 82 147 83
Interest expense                 5,242 6,172 3,389
Depreciation and intangible asset amortization                 21,359 18,101 15,259
Income (loss) before taxes, excluding unallocated corporate activity                 3,813 13,412 8,115
Operating Segments | Other                      
Segment Reporting Information [Line Items]                      
Revenues                 91,854 84,848 74,787
Interest income                 68 0 0
Interest expense                 0 22 38
Depreciation and intangible asset amortization                 1,603 1,542 1,881
Income (loss) before taxes, excluding unallocated corporate activity                 8,647 5,264 2,920
Consolidation, Eliminations                      
Segment Reporting Information [Line Items]                      
Unallocated corporate activity                 (34,156) (30,415) (27,195)
Consolidation, Eliminations | U.S. Regions                      
Segment Reporting Information [Line Items]                      
Unallocated corporate activity                 0 0 0
Consolidation, Eliminations | U.S. Federal                      
Segment Reporting Information [Line Items]                      
Unallocated corporate activity                 0 0 0
Consolidation, Eliminations | Canada                      
Segment Reporting Information [Line Items]                      
Unallocated corporate activity                 0 0 0
Consolidation, Eliminations | Non-Solar DG                      
Segment Reporting Information [Line Items]                      
Unallocated corporate activity                 0 0 0
Consolidation, Eliminations | Other                      
Segment Reporting Information [Line Items]                      
Unallocated corporate activity                 $ 0 $ 0 $ 0