Earnings per Share - Reconciliation of Net Income (Loss) (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Numerator: | |||||||||||
| Net income (loss) attributable to PQ Group Holdings Inc. | $ 28,119 | $ 14,185 | $ 15,782 | $ 214 | $ 65,011 | $ (3,345) | $ (1,609) | $ (2,454) | $ 58,300 | $ 57,603 | $ (79,746) |
| Denominator: | |||||||||||
| Weighted average shares outstanding – Basic (shares) | 133,765,294 | 133,336,352 | 133,222,463 | 133,154,144 | 133,138,140 | 104,096,837 | 104,015,815 | 103,947,888 | 133,380,567 | 111,299,670 | 78,016,005 |
| Weighted average shares outstanding – Diluted (shares) | 134,987,604 | 134,576,162 | 134,209,740 | 133,884,983 | 133,895,646 | 104,096,837 | 104,015,815 | 103,947,888 | 134,684,931 | 111,669,037 | 78,016,005 |
| Net income (loss) per share: | |||||||||||
| Basic income (loss) per share (usd per share) | $ 0.21 | $ 0.11 | $ 0.12 | $ 0.00 | $ 0.49 | $ (0.03) | $ (0.02) | $ (0.02) | $ 0.44 | $ 0.52 | $ (1.02) |
| Diluted income (loss) per share (usd per share) | $ 0.21 | $ 0.11 | $ 0.12 | $ 0.00 | $ 0.49 | $ (0.03) | $ (0.02) | $ (0.02) | $ 0.43 | $ 0.52 | $ (1.02) |
| X | ||||||||||
- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|