Segments and Geographic Area Analysis (Tables)

12 Months Ended

Dec. 31, 2016

Segment Reporting [Abstract]

Revenues from Contract Drilling Services by Equipment Type

Revenues from contract drilling services by equipment-type are listed below:

	Year Ended December 31,
	2016		2015		2014
	(In thousands)
Floaters:
Ultra-Deepwater	$	989,158	$	1,339,059	$	987,565
Deepwater		256,997		548,667		494,247
Mid-Water		248,846		387,549		1,076,842
Total Floaters		1,495,001		2,275,275		2,558,654
Jack-ups		30,213		84,909		178,472
Total contract drilling revenues		1,525,214		2,360,184		2,737,126
Revenues related to reimbursable expenses		75,128		59,209		77,545
Total revenues	$	1,600,342	$	2,419,393	$	2,814,671

Revenues by Geographic Area Presented by Attributing Revenues to Individual Country

Revenues by geographic area are presented by attributing revenues to the individual country or areas where the services were performed.

	Year Ended December 31,
	2016		2015		2014
	(In thousands)
United States	$	548,024	$	513,605	$	418,095
International:
South America		434,956		812,271		1,088,796
Europe/Africa/Mediterranean		344,964		532,824		558,367
Australia/Asia		234,182		415,033		503,814
Mexico		38,216		145,660		245,599
		1,052,318		1,905,788		2,396,576
Total revenues	$	1,600,342	$	2,419,393	$	2,814,671

Individual Countries that Comprised 5% or More of Our Total Contract Drilling Revenues from Unaffiliated Customers

For the years ended December 31, 2016, 2015 and 2014, individual countries that comprised 5% or more of our total contract drilling revenues from unaffiliated customers are listed below.

	Year Ended December 31,
	2016			2015			2014
Brazil		18.0	%		23.1	%		31.0	%
United Kingdom		15.3	%		11.4	%		10.7	%
Australia		12.8	%		7.0	%		6.4	%
Trinidad and Tobago		9.2	%		9.8	%		4.0	%
Romania		4.0	%		9.7	%		3.9	%
Mexico		2.4	%		6.0	%		8.7	%
Malaysia		1.7	%		6.8	%		5.5	%

Long-Lived Tangible Assets by Geographic Location

The following table presents our long-lived tangible assets by geographic location as of December 31, 2016, 2015 and 2014. A substantial portion of our assets is comprised of rigs that are mobile, and therefore asset locations at the end of the period are not necessarily indicative of the geographic distribution of the earnings generated by such assets during the periods and may vary from period to period due to the relocation of rigs. In circumstances where our drilling rigs were in transit at the end of a calendar year, they have been presented in the tables below within the geographic area in which they were expected to operate.

	December 31,
	2016(1)		2015(1)		2014
	(In thousands)
Drilling and other property and equipment, net:
United States	$	2,753,511	$	3,292,474	$	2,637,621
International:
Australia/Asia/Middle East		1,429,563		1,224,089		1,460,841
South America		1,030,069		1,051,283		1,445,832
Europe/Africa/Mediterranean		380,462		664,520		1,128,857
Mexico		133,330		146,448		272,802
		2,973,424		3,086,340		4,308,332
Total	$	5,726,935	$	6,378,814	$	6,945,953

(1) During 2016 and 2015, we recorded an aggregate impairment loss of $678.1 million and $860.4 million, respectively, to write down certain of our drilling rigs and related equipment with indicators of impairment to their estimated recoverable amounts.

Countries Where Parent Company had Material Concentration of Operating Assets

The following table presents the countries in which material concentrations of our long-lived tangible assets were located as of December 31, 2016, 2015 and 2014:

	December 31,
	2016			2015			2014
United States		48.1	%		51.6	%		38.0	%
Brazil Malaysia		16.8 13.6	%  %		15.3 10.4	%  %		20.3 6.6	%  %
South Korea		—			4.2	%		6.3	%
Spain		—			2.7	%		8.1	%
Vietnam		—			—			6.9	%

Revenues from Major Customers that Contributed More than 10% of Total Revenues

Revenues from our major customers for the years ended December 31, 2016, 2015 and 2014 that contributed more than 10% of our total revenues are as follows:

	Year Ended December 31,
Customer	2016			2015			2014
Anadarko		22.4	%		12.4	%		3.6	%
Petróleo Brasileiro S.A.		17.9	%		24.1	%		31.9	%
ExxonMobil		5.8	%		12.4	%		5.0	%