Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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+ Details

- Definition

Loss recognized during the period that results from the write-down of goodwill after comparing the implied fair value of reporting unit goodwill with the carrying amount of that goodwill. Goodwill is assessed at least annually for impairment.

+ References

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+ Details

Summary of Significant Accounting Policies (Details) (USD $) In Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		$ 494,372
Acquisitions		7,619
Impairments	10,700	0	10,707
Cumulative Translation Adjustment		(694)
Ending Balance		501,297
U.S. Lower 48 Land Drilling [Member]
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		30,154
Acquisitions		0
Impairments		0
Cumulative Translation Adjustment		0
Ending Balance		30,154
U.S. Land Well-servicing [Member]
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		55,839
Acquisitions		(767)
Impairments		0
Cumulative Translation Adjustment		0
Ending Balance		55,072
U.S. Offshore [Member]
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		7,296
Acquisitions		0
Impairments		0
Cumulative Translation Adjustment		0
Ending Balance		7,296
Alaska [Member]
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		19,995
Acquisitions		0
Impairments		0
Cumulative Translation Adjustment		0
Ending Balance		19,995
International [Member]
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		18,983
Acquisitions		0
Impairments		0
Cumulative Translation Adjustment		0
Ending Balance		18,983
Subtotal Contract Drilling [Member]
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		132,267
Acquisitions		(767)
Impairments		0
Cumulative Translation Adjustment		0
Ending Balance		131,500
Pressure Pumping [Member]
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		334,992
Acquisitions		0
Impairments		0
Cumulative Translation Adjustment		0
Ending Balance		334,992
Other Operating Segments [Member]
Change in the carrying amount of goodwill for various Contract Drilling segments and other Operating Segments
Beginning Balance		27,113
Acquisitions		8,386
Impairments		0
Cumulative Translation Adjustment		(694)
Ending Balance		$ 34,805