Stock-Based Compensation and Employee Benefit Plans (Summary of Option Activity) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (in shares) | shares	10,711,321
Granted (in shares) | shares	2,240,951
Exercised (in shares) | shares	(559,034)
Forfeited (in shares) | shares	(816,688)
Expired (in shares) | shares	(150,254)
Ending balance (in shares) | shares	11,426,296
Exercisable, number of options (in shares) | shares	6,891,188
Vested or expected to vest, number of options (in shares) | shares	11,215,431
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning balance, weighted-average exercise price (in dollars per share) | $ / shares	$ 6.16
Granted (in dollars per share) | $ / shares	5.81
Exercised (in dollars per share) | $ / shares	0.57
Forfeited (in dollars per share) | $ / shares	8.66
Expired (in dollars per share) | $ / shares	11.75
Ending balance, weighted-average exercise price (in dollars per share) | $ / shares	6.10
Exercisable, weighted-average exercise price (in dollars per share) | $ / shares	4.74
Vested or expected to vest, weighted-average exercise price (in dollars per share) | $ / shares	$ 6.07
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted-average remaining contractual term	7 years 3 months 18 days
Outstanding, aggregate intrinsic value | $	$ 18,928
Exercisable, weighted-average remaining contractual term	6 years 7 months 6 days
Exercisable, aggregate intrinsic value | $	$ 17,103
Vested or expected to vest, weighted-average remaining contractual term	7 years 3 months 18 days
Vested or expected to vest, aggregate intrinsic value | $	$ 18,912