Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2016

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,
	2016	2015	2014
Computation of diluted weighted average shares outstanding:
Basic weighted average shares outstanding	52,276,951	52,274,573	51,757,867
Incremental shares from assumed exercise of stock options and vesting of restricted stock	1,705,224	1,783,199	2,143,173
Incremental shares from assumed conversion of convertible debentures	18,904	18,904	—
Diluted weighted average shares outstanding	54,001,079	54,076,676	53,901,040