Debt - Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Debt maturities
2019	$ 242,250
2020	150,000
Total principal outstanding	392,250	$ 318,500
Unamortized deferred financing costs	(1,243)	$ (821)
Total	$ 391,007