SUMMARY OF ACCOUNTING POLICIES - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands |
Mar. 31, 2019 |
Mar. 31, 2018 |
|---|---|---|
| Accounting Policies [Abstract] | ||
| Cash and bank balances | $ 1,222,737 | $ 1,019,802 |
| Money market funds and time deposits | 473,888 | 452,622 |
| Cash and cash equivalents | $ 1,696,625 | $ 1,472,424 |