Stock-Based Compensation (Additional Information) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Compensation Related Costs Share Based Payments Disclosure [Line Items]
Compensation expense (income)	$ 1,758,000	$ 688,000
Options exercised, total intrinsic value	4,200,000
Total amount of cash received from exercise of options	10,500,000
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
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
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)	600,000	100,000
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)	900,000	300,000
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