Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Federal:
Current	$ 4,810	$ 2,529	$ (1,298)
Deferred	25,955	11,142	(18,606)
Total federal	30,765	13,671	(19,904)
State:
Current	1,914	1,897	1,592
Deferred	2,500	4,153	(951)
Total state	4,414	6,050	641
Total provision for (benefit from) income taxes	35,179	19,721	(19,263)
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Federal statutory tax	35,165	19,459	(22,411)
State taxes, net of federal tax benefit	3,769	5,420	101
Percentage depletion deduction	(1,444)	(1,217)	(787)
Domestic production deduction	(306)	(2)	(27)
Noncontrolling interests	(2,639)	(3,686)	2,920
Nondeductible expenses	219	275	2,384
Other	415	(528)	(1,443)
Total provision for (benefit from) income taxes	$ 35,179	$ 19,721	$ (19,263)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal statutory tax, Percent	34.00%	35.00%	35.00%
State taxes, net of federal tax benefit, Percent	3.60%	9.70%	(0.20%)
Percentage depletion deduction, Percent	(1.40%)	(2.20%)	1.20%
Domestic production deduction, Percent	(0.30%)	0.00%	0.10%
Non-controlling interests, Percent	(2.60%)	(6.60%)	(4.60%)
Nondeductible expenses, Percent	0.20%	0.50%	(3.70%)
Other, Percent	0.50%	(0.90%)	2.30%
Total, Percent	34.00%	35.50%	30.10%
Deferred tax assets:
Receivables				$ 332	$ 306
Inventory				2,710	3,579
Insurance				10,427	11,534
Deferred compensation				11,139	12,479
Other accrued liabilities				3,405	4,801
Contract income recognition				0	5,592
Impairments on real estate investments				485	11,329
Accrued compensation				12,639	7,524
Other				2,925	2,107
Net operating loss carryforward				648	8,665
Valuation allowance	$ 1,185	$ 3,731	$ 5,242	641	1,185
Total deferred tax assets				44,069	66,731
Deferred tax liabilities:
Property and equipment				30,285	33,946
Contract income recognition				9,455	0
Total long-term deferred tax liabilities				39,740	33,946
Net long-term deferred tax assets				4,329	32,785
Deferred Tax Assets, Valuation Allowance [Roll Forward]
Beginning balance	1,185	3,731	5,242
Deductions, net	(544)	(2,546)	(1,511)
Ending balance	641	1,185	3,731
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	900
Ending balance	1,600	900
Unrecognized Tax Benefits	900	900		1,600	900
Unrecognized Tax Benefits that Would Impact Effective Tax Rate				1,300	500
Unrecognized Tax Benefits, Interest on Income Taxes Expense	(100)	900	(100)
Unrecognized Tax Benefits, Interest on Income Taxes Accrued				100	200
Other Long Term Liabilities [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	887	2,231	2,315
Gross increases – current period tax positions	1,006	0	363
Gross decreases – current period tax positions	(156)	(282)	(638)
Gross increases – prior period tax positions	0	0	508
Gross decreases – prior period tax positions	0	(2)	(2)
Settlements with taxing authorities/lapse of statute of limitations	(159)	(1,060)	(315)
Ending balance	1,578	887	2,231
Unrecognized Tax Benefits	$ 887	$ 2,231	$ 2,315	$ 1,578	$ 887