Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2014

Stockholders' Equity Note [Abstract]

Schedule of Weighted Average Number of Shares [Table Text Block]

The following table provides the computation of diluted weighted average number of common shares outstanding:

	Year Ended December 31,
	2014	2013	2012
Computation of diluted weighted average shares outstanding:
Basic weighted average shares outstanding	51,757,867	49,964,819	50,529,476
Incremental shares from assumed exercise of stock options and vesting of restricted stock	2,143,173	1,953,484	883,034
Incremental shares from assumed conversion of convertible debentures	—	64,317	—
Diluted weighted average shares outstanding	53,901,040	51,982,620	51,412,510