using System;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		var input = @"\a{Doc Title}\aDoc ID\rDoc Date\rDoc Version\rDoc Status\a:\r:\r:\r:\a{DocID}\r{DocDate}\r{DocVersion}\r{DocStatus}\a\a\r";
		var pattern = @"(?>\\[ar]:?)+";
		var items = Regex.Split(input, pattern);
		foreach (var item in items)
		    if (!string.IsNullOrWhiteSpace(item))
		        Console.WriteLine(item);
	}
}