SQL Partition Dates

I have data such as this: ID|From Date |To Date 1 |01/01/2014 |04/01/2015 1 |04/01/2015 |01/01/2016 1 |01/01/2016 |12/31/2016 But I would like this as the end result: ID|From Date |To Date 1 |01/01/2014 |12/31/2016 I tried partitioning, but I'm not quite familiar with how it works. Any suggestions would be greatly appreciated. Thanks!