Fair Value Measurements (Details 1) - USD ($)	Jun. 30, 2015	Apr. 14, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior unsecured notes	$ 390,667,000		$ 0
Senior Notes Due 2023 | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes Payable, Fair Value Disclosure	$ 408,500,000
Senior unsecured notes		$ 400,000,000	$ 0