Transferwise have just announced that they have reduced their fees for sending money to Indonesia. You can see their pricing here:
https://transferwise.com/pricing#?from=AUD&to=IDR
Personally, I think they're the cheapest and easiest way to send money. Please let me know if you've found a better option.
Revolut is potentially a little cheaper. They charge £5 UK, €6 europe, elsewhere €30, one-off, for a physical debit card that they send to you.
Balances can be held in GBP, Eur, or USD only.
Payment/ATM withdrawals can be made in almost any currency, at a rate of 0.5%. Some currencies they don't offer 0.5%, due to illiquidity. These include THB, but not, interestingly, IDR. They accept topups via debit card (free except in the US) or bank transfer (outside of the EU you will probably have to pay to send them money). From Friday to Sunday (UTC, presumably) they add on 0.5% (major currencies) (1.0% other currencies) to their spread to cover the risk of currency fluctuations.
So realistically it is probably only useful for UK and eurozone customers, due to only supporting GBP, USD and EUR as base currencies, and the cost of getting money in for US customers.
There is a maximum of £200 in ATM withdrawals per month - after that you pay 2% ATM fee). The overall cap is £5000/month (so you can withdraw £200/month from an ATM, but can spend a further £4800 in retail outlets - they support bank transfers for some currencies, but not Indonesia).
So in summary:
Monday - Thursday: 0.5% currency markup
Friday - Sunday: 1.5% currency markup
with a max £/€200 ATM withdrawals per month and £/€5000 overall spend