From someone who receives packages regularly from the US(from letters to packages), don't ship this 100 pages document by usps priority mail(1 week delivery but no tracking, no guarantee). Your next choice is usps registered mail. Whatever the weight of the document, normal airmail + 7.5 $ to make it registered. Generally 10-15 days. Then there's speed post(EMS), 3-7 days and 100 $ insured for free. Tracking available. If the 100 pages weigh less than 1 pound(4x0 grams), then cost is around 20.50-22.50 $.
If you're not in a hurry, send it by registered post and relaaax. It'll get there.