Sale of Assets (Details) $ in Thousands			3 Months Ended
	Mar. 31, 2017 USD ($) location	May 02, 2016 USD ($) location	Mar. 31, 2017 USD ($) location	Mar. 31, 2016 USD ($)
Business Acquisition [Line Items]
Proceeds from sale of assets			$ 13,787	$ 15,013
Farm Center [Member] | Florida
Business Acquisition [Line Items]
Number of locations sold | location	4		4
Proceeds from sale of assets	$ 17,400
Gain on sale of assets	4,700
Working capital adjustment receivable	$ 3,600		$ 3,600
Grain and Agronomy [Member] | Iowa
Business Acquisition [Line Items]
Number of locations sold | location		8
Proceeds from sale of assets		$ 54,300