Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Supplemental non-cash investing and financing activities:
Value of common stock issued in acquisitions	$ 0	$ 1,014
Exercise of stock options by common stock surrender	0	66
Supplemental cash payment information:
Interest paid	382	309
Income taxes paid, net of refunds	$ 2,264	$ 1,911