Subsequent Events (Details) - USD ($)	Jan. 31, 2017	Nov. 30, 2015
New Credit Agreement
Subsequent Event [Line Items]
Maximum borrowing capacity		$ 175,000,000
Debt term		5 years
Additional borrowing amount		$ 75,000,000
New Credit Agreement | Oil and Gas
Subsequent Event [Line Items]
Borrowings		102,000,000
New Credit Agreement | Subsequent Event | Oil and Gas
Subsequent Event [Line Items]
Repayment of Principal at Inception	$ 15,000,000
Borrowings	69,375,000
Revolving Credit Facility | New Credit Agreement
Subsequent Event [Line Items]
Maximum borrowing capacity		$ 100,000,000
Debt term		5 years
Revolving Credit Facility | New Credit Agreement | Oil and Gas
Subsequent Event [Line Items]
Borrowings		$ 27,000,000
Letters of Credit | New Credit Agreement
Subsequent Event [Line Items]
Maximum borrowing capacity		$ 15,000,000
Minimum | New Credit Agreement
Subsequent Event [Line Items]
Unused borrowing capacity, fee		0.20%
Fixed charge coverage ratio		1.25
Minimum | Letters of Credit | New Credit Agreement
Subsequent Event [Line Items]
Debt issuance costs, fee		1.50%
Minimum | LIBOR | New Credit Agreement
Subsequent Event [Line Items]
Variable rate of debt		1.50%
Minimum | Base Rate | New Credit Agreement
Subsequent Event [Line Items]
Variable rate of debt		0.50%
Maximum | New Credit Agreement
Subsequent Event [Line Items]
Unused borrowing capacity, fee		0.375%
Leverage ratio		3.00
Maximum | Letters of Credit | New Credit Agreement
Subsequent Event [Line Items]
Debt issuance costs, fee		2.25%
Maximum | LIBOR | New Credit Agreement
Subsequent Event [Line Items]
Variable rate of debt		2.25%
Maximum | Base Rate | New Credit Agreement
Subsequent Event [Line Items]
Variable rate of debt		1.25%
Line of Credit | Revolving Credit Facility | Subsequent Event
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 250,000,000
Debt term	5 years
Additional borrowing amount	$ 75,000,000
Line of Credit | Revolving Credit Facility | Subsequent Event | Oil and Gas
Subsequent Event [Line Items]
Borrowings	54,375,000
Line of Credit | Letters of Credit | Subsequent Event
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 15,000,000
Line of Credit | Minimum | Revolving Credit Facility | Subsequent Event
Subsequent Event [Line Items]
Unused borrowing capacity, fee	0.20%
Fixed charge coverage ratio	1.25
Line of Credit | Minimum | Letters of Credit | Subsequent Event
Subsequent Event [Line Items]
Debt issuance costs, fee	1.50%
Line of Credit | Minimum | LIBOR | Revolving Credit Facility | Subsequent Event
Subsequent Event [Line Items]
Variable rate of debt	1.50%
Line of Credit | Minimum | Base Rate | Revolving Credit Facility | Subsequent Event
Subsequent Event [Line Items]
Variable rate of debt	0.50%
Line of Credit | Maximum | Revolving Credit Facility | Subsequent Event
Subsequent Event [Line Items]
Unused borrowing capacity, fee	0.50%
Leverage ratio	3.00
Line of Credit | Maximum | Letters of Credit | Subsequent Event
Subsequent Event [Line Items]
Debt issuance costs, fee	2.75%
Line of Credit | Maximum | LIBOR | Revolving Credit Facility | Subsequent Event
Subsequent Event [Line Items]
Variable rate of debt	2.75%
Line of Credit | Maximum | Base Rate | Revolving Credit Facility | Subsequent Event
Subsequent Event [Line Items]
Variable rate of debt	1.75%