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Supplemental Financial Information (Schedule of Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017
Schedule Of Supplemental Financial Information [Line Items] |  |  |  |
Net sales: | $ 266,036 | $ 247,627 | $ 481,373 | $ 454,232
Cost of sales | 195,533 | 185,802 | 362,552 | 343,152
Gross profit | 70,503 | 61,825 | 118,821 | 111,080
Selling, general, and administrative expense | 38,229 | 36,895 | 72,704 | 76,471
Income from operations | 32,274 | 24,930 | 46,117 | 34,609
Interest expense | 3,130 | 3,550 | 6,399 | 7,126
Other expense (income) | 13 | 353 | (572) | 407
Income before taxes | 29,131 | 21,027 | 40,290 | 27,076
Provision for income taxes | 6,294 | 7,853 | 9,101 | 9,906
Income from continuing operations | 22,837 | 13,174 | 31,189 | 17,170
Loss before taxes | 0 | (644) | 0 | (644)
Benefit of income taxes | 0 | (239) | 0 | (239)
Loss from discontinued operations | 0 | (405) | 0 | (405)
Equity in earnings (loss) from subsidiaries | 0 | 0 | 0 | 0
Net income | 22,837 | 12,769 | 31,189 | 16,765
Reportable Legal Entities | Guarantor Subsidiaries |  |  |  |
Schedule Of Supplemental Financial Information [Line Items] |  |  |  |
Net sales: | 256,487 | 238,652 | 460,954 | 436,400
Cost of sales | 189,082 | 178,779 | 347,666 | 329,286
Gross profit | 67,405 | 59,873 | 113,288 | 107,114
Selling, general, and administrative expense | 36,449 | 33,681 | 69,173 | 70,187
Income from operations | 30,956 | 26,192 | 44,115 | 36,927
Interest expense | (213) | 162 | (297) | 354
Other expense (income) | 111 | 115 | 139 | 245
Income before taxes | 31,058 | 25,915 | 44,273 | 36,328
Provision for income taxes | 6,874 | 9,360 | 10,209 | 12,738
Income from continuing operations |  | 16,555 |  | 23,590
Loss before taxes |  | (644) |  | (644)
Benefit of income taxes |  | (239) |  | (239)
Loss from discontinued operations |  | (405) |  | (405)
Equity in earnings (loss) from subsidiaries | 1,334 | (1,348) | 2,424 | (2,040)
Net income | 25,518 | 14,802 | 36,488 | 21,145
Reportable Legal Entities | Non-Guarantor Subsidiaries |  |  |  |
Schedule Of Supplemental Financial Information [Line Items] |  |  |  |
Net sales: | 14,194 | 10,627 | 26,524 | 21,869
Cost of sales | 10,891 | 8,739 | 20,649 | 17,721
Gross profit | 3,303 | 1,888 | 5,875 | 4,148
Selling, general, and administrative expense | 1,744 | 3,180 | 3,451 | 6,207
Income from operations | 1,559 | (1,292) | 2,424 | (2,059)
Interest expense | (59) | (15) | (108) | (33)
Other expense (income) | (98) | 238 | (711) | 162
Income before taxes | 1,716 | (1,515) | 3,243 | (2,188)
Provision for income taxes | 382 | (167) | 819 | (148)
Income from continuing operations |  | (1,348) |  | (2,040)
Loss before taxes |  | 0 |  | 0
Benefit of income taxes |  | 0 |  | 0
Loss from discontinued operations |  | 0 |  | 0
Equity in earnings (loss) from subsidiaries | 0 | 0 | 0 | 0
Net income | 1,334 | (1,348) | 2,424 | (2,040)
Reportable Legal Entities | Gibraltar Industries, Inc. |  |  |  |
Schedule Of Supplemental Financial Information [Line Items] |  |  |  |
Net sales: | 0 | 0 | 0 | 0
Cost of sales | 0 | 0 | 0 | 0
Gross profit | 0 | 0 | 0 | 0
Selling, general, and administrative expense | 36 | 34 | 80 | 77
Income from operations | (36) | (34) | (80) | (77)
Interest expense | 3,402 | 3,403 | 6,804 | 6,805
Other expense (income) | 0 | 0 | 0 | 0
Income before taxes | (3,438) | (3,437) | (6,884) | (6,882)
Provision for income taxes | (962) | (1,340) | (1,927) | (2,684)
Income from continuing operations |  | (2,097) |  | (4,198)
Loss before taxes |  | 0 |  | 0
Benefit of income taxes |  | 0 |  | 0
Loss from discontinued operations |  | 0 |  | 0
Equity in earnings (loss) from subsidiaries | 25,518 | 14,802 | 36,488 | 21,145
Net income | 23,042 | 12,705 | 31,531 | 16,947
Eliminations |  |  |  |
Schedule Of Supplemental Financial Information [Line Items] |  |  |  |
Net sales: | (4,645) | (1,652) | (6,105) | (4,037)
Cost of sales | (4,440) | (1,716) | (5,763) | (3,855)
Gross profit | (205) | 64 | (342) | (182)
Selling, general, and administrative expense | 0 | 0 | 0 | 0
Income from operations | (205) | 64 | (342) | (182)
Interest expense | 0 | 0 | 0 | 0
Other expense (income) | 0 | 0 | 0 | 0
Income before taxes | (205) | 64 | (342) | (182)
Provision for income taxes | 0 | 0 | 0 | 0
Income from continuing operations |  | 64 |  | (182)
Loss before taxes |  | 0 |  | 0
Benefit of income taxes |  | 0 |  | 0
Loss from discontinued operations |  | 0 |  | 0
Equity in earnings (loss) from subsidiaries | (26,852) | (13,454) | (38,912) | (19,105)
Net income | $ (27,057) | $ (13,390) | $ (39,254) | $ (19,287)

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