Long-Term Debt - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended		9 Months Ended				1 Months Ended		1 Months Ended	9 Months Ended		9 Months Ended				1 Months Ended			1 Months Ended							0 Months Ended
	Aug. 05, 2013	Jul. 31, 2013	Mar. 31, 2010	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013	Dec. 31, 2012	Jul. 31, 2013 Notes Payable to Banks [Member]	Oct. 31, 2011 Notes Payable to Banks [Member]	Jun. 30, 2013 Secured Debt [Member] OCTEG-KCA [Member]	Sep. 30, 2013 Secured Debt [Member] OCTEG-KCA [Member]	Jun. 05, 2013 Secured Debt [Member] OCTEG-KCA [Member]	Sep. 30, 2013 Swingline Facilty [Member] OCTEG-KCA [Member]	Jul. 02, 2013 Swingline Facilty [Member] OCTEG-KCA [Member]	Jul. 02, 2013 Revolving Credit Facility [Member] Jefferies Finance LLC and Goldman Sachs Bank USA [Member]	Jul. 02, 2013 Revolving Credit Facility [Member] OCTEG-KCA [Member]	Jul. 31, 2013 Secured Debt [Member] Jefferies Finance LLC and Goldman Sachs Bank USA [Member]	Sep. 30, 2013 Secured Debt [Member] Jefferies Finance LLC and Goldman Sachs Bank USA [Member]	Jul. 02, 2013 Secured Debt [Member] Jefferies Finance LLC and Goldman Sachs Bank USA [Member]	Jul. 31, 2013 Secured Debt [Member] OCTEG-KCA [Member]	Jul. 02, 2013 Secured Debt [Member] OCTEG-KCA [Member]	Jul. 02, 2013 LIBOR Floor [Member] Secured Debt [Member] Jefferies Finance LLC and Goldman Sachs Bank USA [Member]	Jul. 02, 2013 Prime Rate [Member] Secured Debt [Member] Jefferies Finance LLC and Goldman Sachs Bank USA [Member]	Jun. 30, 2013 Borrowing Base A [Member] Revolving Credit Facility [Member] OCTEG-KCA [Member]	Jun. 30, 2013 Borrowing Base B Loan [Member] Revolving Credit Facility [Member] OCTEG-KCA [Member]	Jul. 02, 2013 LIBOR [Member] Secured Debt [Member] Jefferies Finance LLC and Goldman Sachs Bank USA [Member]	Oct. 23, 2013 Subsequent Event [Member] Secured Debt [Member] OCTEG-KCA [Member]	Oct. 23, 2013 Subsequent Event [Member] Revolving Credit Facility [Member]	Sep. 30, 2013 Other Assets [Member]
Line of Credit Facility [Line Items]
Debt amount									$ 15,000,000.0
Interest rate									5.95%			8.25%
Number of days to issue securities											365 days
Early repayment fee								3,000,000
Term credit agreement				535,000,000			0					305,000,000							535,000,000		450,000,000
Escrow agent fees and expenses										3,000,000
Additional interest percent obligation from guarantor if certain obligations are not met											1.00%
Revolving credit facility amount														50,000,000.0	50,000,000.0	750,000,000.0
Amount outstanding															0
increase in line of credit facility, maximum borrowing capacity																300,000,000.0
Interest rate of credit agreement																						1.25%	2.25%			1.00%
Percentage points added to interest rate base																			4.50%				0.50%	1.75%	2.25%	3.50%
Interest rate at end of period																		5.75%
Principal payments in 2014																			235,000,000
Periodic principal payment																	7,500,000
Commitment fee percentage of average daily amount unused portion of revolving credit agreement																				0.35%
Prepayment premium percentage																		1.00%
Loan guarantee percent																		100.00%
Debt issuance costs incurred											34,600,000		1,200,000
Effective interest rate											9.00%							7.60%
Early principal payments																											200,000,000	200,000,000
Issue of cash convertible senior subordinated notes			375,000,000			375,000,000
Cash convertible senior subordinated notes due date			Mar. 15, 2015
Notes bear interest rate per year				3.50%
Date of commencing of notes				Sep. 15, 2010
Date of mature of notes				Mar. 15, 2015
Deposit cash made to credit facilty to repurchase convertible notes		375,000,000
Repayments of convertible debt	257,700,000			257,741,000	0
Interest payable	3,600,000
Cash collateral for borrowed securities																													$ 117,300,000