Stock Incentive Plans (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Stock Incentive Plans [Line Items]
Number of common stock authorized for Long-Term Incentive Plan	6,200,000		6,200,000
Stock-based compensation expense	$ 11,124,000	$ 14,170,000	$ 20,178,000	$ 21,837,000
Maximum [Member]
Stock Incentive Plans [Line Items]
Vesting period			5 years
Minimum [Member]
Stock Incentive Plans [Line Items]
Vesting period			3 years
Employee Stock Option [Member] | Employee Stock Option [Member]
Stock Incentive Plans [Line Items]
Vesting period			10 years
Employee Stock Option [Member] | Employee Stock Option [Member] | Director [Member]
Stock Incentive Plans [Line Items]
Vesting period			3 years
Employee Stock Option [Member] | Employee Stock Option [Member] | Officer [Member]
Stock Incentive Plans [Line Items]
Vesting period			5 years