Consolidated Statements of Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Maintenance Revenue	$ 15,726	$ (4,189)	$ 55,148	$ 35,035
Non-cash share based payment expense	$ 1,424	$ 949	$ 3,981	$ 3,167