Stock-Based Compensation (Additional Information) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Compensation expense (income)			$ 5,652,000	$ 3,704,000
Options exercised, total intrinsic value			6,700,000
Total amount of cash received from exercise of options			15,600,000
Employee stock purchase plan, number of offering (offering period)			2
Employee stock purchase plan, offering period (months)			6 months
Employee Stock Purchase Plan [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Compensation expense (income)	100,000	100,000	300,000	300,000
Employee stock purchase plan, purchase price discount (percent)			15.00%
Stock Options [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Stock options, contractual term (years)			10 years
Stock-based compensation, approximate forfeitures rate (percent)			3.00%
Compensation expense (income)	100,000	(300,000)	300,000	300,000
Stock Options [Member] | Employee Severance [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Compensation expense (income)		200,000
Stock Options [Member] | Employee Severance [Member] | Modification of Stock Option Grant [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Compensation expense (income)		700,000
Performance-Based Restricted Stock [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Stock-based compensation, approximate forfeitures rate (percent)			7.00%
Compensation expense (income)	200,000	500,000	1,500,000	600,000
Restricted stock award program, measurement period (years)			3 years
Expected dividend yield (percent)			0.00%	0.00%
Restricted stock award program, payment of award as percentage of target (percent)					108.30%
Performance-Based Restricted Stock [Member] | Minimum [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Restricted stock award program, awarded shares as a percentage of the original award amount (percent)			0.00%
Performance-Based Restricted Stock [Member] | Maximum [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Restricted stock award program, awarded shares as a percentage of the original award amount (percent)			200.00%
Time Based Restricted Stock [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Stock-based compensation, approximate forfeitures rate (percent)			7.00%
Compensation expense (income)	700,000	1,200,000	2,700,000	1,800,000
Restricted stock award program, vesting period (years)			3 years
Deferred Stock Units [Member]
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Compensation expense (income)	$ 0	$ 0	$ 800,000	$ 700,000