Stocholders' Equity (Tables)

9 Months Ended

Sep. 30, 2018

Earnings Per Share [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:

	Three Months Ended September 30,		Nine Months Ended September 30,
	2018	2017	2018	2017
Computation of diluted weighted average shares outstanding:
Basic weighted average shares outstanding	51,182,502	52,590,837	51,436,228	52,463,511
Incremental shares from assumed exercise of stock options and vesting of restricted stock	1,521,560	1,863,883	1,525,204	1,789,307
Incremental shares from assumed conversion of convertible notes	1,559,830	1,329,765	1,559,830	1,329,765
Diluted weighted average shares outstanding	54,263,892	55,784,485	54,521,262	55,582,583