Financial Instruments and Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2014	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained interest promissory note receivable	$ 15,000
Notes, maturity period	15 years
Debt principal amount		$ 180,000
Debt interest rate		4.80%
Senior Notes Held By Special Purpose Entity	$ 176,201		$ 176,094
Unamortized discount and debt issuance costs	662		720
Carrying Value | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained interest, fair value	10,429		10,246
Senior Notes Held By Special Purpose Entity	176,201		$ 176,094
AgReserves Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note received in sale of real estate		$ 200,000
Maturity of installment note		15 years
Subsidiaries | Notes Receivable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Issue price of Senior Secured Notes		98.50%
Buyer Special Purpose Entity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Time Deposits Held By Special Purpose Entities	200,000
Special Purpose Entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Treasuries Held By Special Purpose Entities	8,100
Cash Held By Special Purpose Entities	400
Senior Notes Held By Special Purpose Entity	176,200
Unamortized discount and debt issuance costs	$ 3,800
Special Purpose Entities | Notes Receivable
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt interest rate	4.006%
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note maturity year	2022
Retained interest, effective interest rate	3.70%
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note maturity year	2024
Retained interest, effective interest rate	11.30%