Summary of Significant Accounting Policies - Accounts Receivable, net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Jun. 30, 2016
Accounts Receivable, net
Allowance for uncollectible receivables		$ 0.1
Accounts receivable written off	$ 0.0
Allowance for expected sales deductions	$ 3.8	$ 4.8
7.50% Convertible Senior Secured Notes due 2019
Deferred Financing Costs
Interest rate (as a percent)		7.50%