Because of federal privacy laws, cellular companies do not provide detailed reports of content sent via text messaging. In cases of harassment or threatening messages, a lawyer can petition for a court order releasing records held by the carrier, but each carrier has policies for how long messages are kept.
A customer's monthly bill has details of texts sent and received by time and date. Cellular providers are under no regulations to maintain content sent via text and most either purge the information immediately or within days. The easiest method of seeing text content is by accessing the device it was sent from or to, but privacy laws govern this as well.