Capital Stock (Details) (Agreement with Helmerich and Payne International Drilling Co. [Member], USD $)	Jun. 13, 2013	May 23, 2013
Agreement with Helmerich and Payne International Drilling Co. [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, amount (in shares)		2,000,000
Stock repurchase program, cash payment amount		$ 107,100,000
Stock repurchase program, agreement cash payment amount, additional consideration	$ 200,000

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

Name:	us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant