Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Supplemental non-cash investing and financing activities:
Value of common stock issued in acquisitions	$ 1,014	$ 2,043
Final Florida Chemical acquisition adjustment	0	1,162
Value of common stock issued in payment of accrued liability	0	600
Exercise of stock options by common stock surrender	1,126	1,183
Supplemental cash payment information:
Interest paid	1,043	1,038
Income taxes paid	$ 3,044	$ 18,393