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Stock and Stock-Based Incentive Plans Stock and Stock-Based Incentive Plans (Composition of Share-Based Compensation Expense - By Grant Type) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Aug. 31, 2017 | Aug. 31, 2016 | Aug. 31, 2017 | Aug. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation expense, before income taxes | $ 18,240 | $ 29,480 | $ 37,380 | $ 61,327
Stock options |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation expense, before income taxes | 5,916 | 15,090 | 16,286 | 28,221
Cash-settled restricted stock units (RSUs) |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation expense, before income taxes | 9,785 | 9,085 | 12,903 | 21,461
Stock-settled market stock units (MSUs) |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation expense, before income taxes | 2,543 | 3,698 | 6,164 | 7,348
Stock-settled performance stock units (PSUs) |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation expense, before income taxes | (863) | 199 | 490 | 2,332
Employee stock purchase plan |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation expense, before income taxes | 381 | 355 | 795 | 765
Restricted stock awards (RSAs) |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share-based compensation expense, before income taxes | $ 478 | $ 1,053 | $ 742 | $ 1,200

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