(Unaudited, in thousands)
Three Months Ended June 30, | Six Months Ended June 30, | |||||||||||||||
2021 | 2020 | 2021 | 2020 | |||||||||||||
Total operating expenses | $ | 103,587 | $ | 74,638 | $ | 198,560 | $ | 135,099 | ||||||||
Adjustments to reconcile total operating expenses to non-GAAP total operating expenses: | ||||||||||||||||
Stock-based compensation expense | (31,241 | ) | (20,402 | ) | (59,010 | ) | (38,407 | ) | ||||||||
Deferred compensation plan income (expense) | (2,022 | ) | (3,572 | ) | (2,981 | ) | 30 | |||||||||
Non-GAAP operating expenses | $ | 70,324 | $ | 50,664 | $ | 136,569 | $ | 96,722 |