Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current taxes:
Federal	$ (12,021)	$ 473	$ 144
State	1,022	21	198
Deferred taxes:
Federal	8,237	(104)	(2,805)
State	(3,699)	4,047	264
Income tax expense (benefit)	(6,461)	4,437	$ (2,199)
Operating Loss Carryforwards [Line Items]
Material Uncertain Tax Position	$ 0	$ 0
Effective income tax rate reconciliation [Abstract]
Federal statutory rate	35.00%	35.00%	35.00%
State, net of federal tax benefit	0.10%	(0.90%)	(0.10%)
Loss excluded from nontaxable entities	(34.80%)	(34.60%)	(34.60%)
Other	(0.20%)	(0.50%)	0.00%
Effective rate	0.10%	(1.00%)	0.30%
Deferred tax assets:
Net operating loss carryforwards	$ 370	$ 0
Unit-based compensation	18,214	22,105
Valuation allowance	(2,159)	0
Other	7,300	6,857
Total deferred tax assets	23,725	28,962
Deferred tax liabilities:
Property and equipment principally due to differences in depreciation	(12,534)	(10,991)
Other	8	(6,370)
Total deferred tax liabilities	(12,526)	(17,361)
Net deferred tax assets	11,199	11,601
Net deferred tax assets and liabilities classified in consolidated balance sheets [Abstract]
Deferred tax assets	23,188	28,442
Deferred tax liabilities	(675)	(2,964)
Other current assets	22,513	25,478
Deferred tax assets	537	520
Deferred tax liabilities	(11,314)	(13,877)
Deferred Tax Liabilities, Gross, Noncurrent	11,851	$ 14,397
Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 1,000
Net operating loss carryforwards, expiration dates	Dec. 31, 2036