Stock-Based Compensation (Stock Options Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Vested and Expected to Vest, December 31, 2014 Number of Stock Options (Shares)	31,500		40,000		40,000
Employee Stock Option | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding — January 1 (in shares)	4,370,826
Granted (in shares)	1,418,087
Exercised (in shares)	314,563
Forfeited (in shares)	(208,014)
Expired (in shares)	(20,024)
Outstanding — December 31 (in shares)	5,246,312		4,370,826
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding — January 1 (USD per share)	$ 7.60
Granted (USD per share)	$ 13.37
Exercised (USD per share)	$ 5.65
Forfeited (USD per share)	$ 12.16
Expired (USD per share)	$ 13.84
Outstanding — December 31 (USD per share)	$ 9.07		$ 7.60
Outstanding, Weighted Average Remaining Contractual Term (Years)	6 years 4 months 24 days
Outstanding, Aggregate Intrinsic Value	$ 32,829	[1]
Aggregate Intrinsic Value	2,622	[2]	11,000	[2]	11,100	[2]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Vested and Expected to Vest, December 31, 2014 Number of Stock Options (Shares)	4,795,880
Vested and Expected to Vest, December 31, 2014 Outstanding, Weighted Average Exercise Price (USD per share)	$ 8.65
Vested and Expected to Vest, December 31, 2014 Weighted Average Remaining Contractual Term	6 years 2 months 8 days
Vested and Expected to Vest, December 31, 2014 Aggregate Intrinsic Value	31,978	[1]
Vested, December 31, 2014 Number of Stock Options (Shares)	3,070,114
Vested, December 31, 2014 Weighted Average Exercise Price (USD per share)	$ 6.22
Vested, December 31, 2014 Weighted Average Remaining Contractual Term (Years)	4 years 10 months 17 days
Vested, December 31, 2014 Aggregate Intrinsic Value	$ 27,878	[1]

[1] Represents the total difference between the Company's closing stock price on the last trading day of period reported on and the stock option exercise price, multiplied by the number of in-the-money options as of the period reported on. The amount of intrinsic value will change based on the fair market value of the Company's stock.

[2] Represents the total difference between the Company's stock price at the time of exercise and the stock option exercise price, multiplied by the number of options exercised.