Stock-Based Compensation - Summary of Changes in Stock Options Outstanding (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Weighted average exercise price (in dollars per share):
Options exercisable at end of period	$ 11.00		$ 11.00
Employee Stock option
Number of Options (in shares):
Options outstanding at beginning of period	1.9	2.6	2.6
Granted	0.2	0.4
Exercised	0	0
Canceled	(0.1)	(1.1)
Options outstanding at end of period	2.0	1.9	2.0	2.6
Options exercisable at end of period	1.0		1.0
Options outstanding, weighted average remaining contract term (in years)		7 years 8 months 12 days	7 years 4 months 24 days	4 years 2 months 12 days
Options exercisable, Weighted average remaining contract term (in years)			5 years 10 months 24 days
Weighted average exercise price (in dollars per share):
Options outstanding at beginning of period	$ 12.62	$ 10.46	$ 10.46
Granted	$ 8.94	$ 16.03
Exercised	$ 0.00	$ 0.00
Canceled	$ 13.88	$ 9.04
Options outstanding at end of period	$ 12.34	$ 12.62	$ 12.34	$ 10.46
Aggregate Intrinsic Value:
Options outstanding at beginning of period	$ 0	$ 17.8	$ 17.8
Exercised	0	0
Options outstanding at end of period	2.3	0	2.3	17.8
Options exercisable at end of period	$ 1.5		$ 1.5