Summary of Significant Accounting Policies (Recently Adopted Accounting Standards) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2013	Jun. 30, 2015	Dec. 31, 2014
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unamortized debt issuance expenses			$ 3.7
Accounting Standards Update 2014-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in accounting principle, effect of adoption	$ 3.1
Other Assets | Accounting Standards Update 2015-3
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unamortized debt issuance expenses		$ (3.7)
Long-term Debt | Accounting Standards Update 2015-3
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unamortized debt issuance expenses		$ 3.7