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If the property is given while the owner is alive - that is a gift; If however the property is transferred because of the owner's death - that is an inheritance.
Either gift or inheritance are not taxable income.
Regardless of the value. Please see for reference IRS publication 525 page 34 (left column)- http://www.irs.gov/pub/irs-pdf/p525.pdf
Gifts and inheritances. Generally, property you receive as a gift, bequest, or inheritance is not included in your income. However, if property you receive this way later produces income such as interest, dividends, or rents, that income is taxable to you. If property is given to a trust and the income from it is paid, credited, or distributed to you, that income is also taxable to you. If the gift, bequest, or inheritance is the income from the property, that income is taxable to you.
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Federal estate taxes are based on if the deceased was an US citizen or if any part of the estate locates in the US. If your deceased relative was not a resident of the US and did not have any property in the US - the estate is not a subject of US tax law.
If the amount is more than $100,000, you are required to file form 3120 - http://www.irs.gov/pub/irs-pdf/f3520.pdf (see instructions for details - http://www.irs.gov/pub/irs-pdf/i3520.pdf) to declare transfer from the foreign country. There is no tax associated with this form.
The fact of transferring the money to the US is not reported to the IRS.
Also - be sure to consult with your banker before initiating the transfer - the bank might ask for additional information because of the large amount.
There is no specific documentation requirements - you might asked to disclose the source of funds and any documents that support your position will be accepted.