Stock-Based Compensation and Employee Benefit Plans (Summary of Option Activity) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Number of Options
Beginning balance (in shares) | shares	7,932,782
Exercised (in shares) | shares	(528,006)
Expired (in shares) | shares	(582,557)
Ending balance (in shares) | shares	6,822,219
Exercisable, number of options (in shares) | shares	6,133,031
Vested or expected to vest, number of options (in shares) | shares	6,789,430
Weighted- Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 5.86
Exercised (in dollars per share) | $ / shares	2.33
Expired (in dollars per share) | $ / shares	11.16
Ending balance (in dollars per share) | $ / shares	5.68
Exercisable, weighted-average exercise price (in dollars per share) | $ / shares	5.68
Vested or expected to vest, weighted-average exercise price (in dollars per share) | $ / shares	$ 5.68
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted-average remaining contractual term	5 years 1 month
Outstanding, aggregate intrinsic value | $	$ 8,648
Exercisable, weighted-average remaining contractual term	4 years 9 months 7 days
Exercisable, aggregate intrinsic value | $	$ 8,648
Vested or expected to vest, weighted-average remaining contractual term	5 years 1 month
Vested or expected to vest, aggregate intrinsic value | $	$ 8,648