Segments and Geographic Area Analysis - Revenues from Contract Drilling Services by Equipment Type (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Contract drilling									$ 2,843,584	$ 2,936,066	$ 3,254,313
Revenues related to reimbursable expenses									76,837	50,442	68,106
Total revenues	726,497	706,165	758,018	729,741	750,537	729,141	738,188	768,642	2,920,421	2,986,508	3,322,419
Ultra-deepwater semisubmersible [Member]
Segment Reporting Information [Line Items]
Contract drilling									854,515	902,793	841,565
Deepwater [Member]
Segment Reporting Information [Line Items]
Contract drilling									617,080	597,694	733,037
Mid-Water [Member]
Segment Reporting Information [Line Items]
Contract drilling									1,197,934	1,275,068	1,482,032
Total Floaters [Member]
Segment Reporting Information [Line Items]
Contract drilling									2,669,529	2,775,555	3,056,634
Jack-ups [Member]
Segment Reporting Information [Line Items]
Contract drilling									174,055	160,511	197,534
Other [Member]
Segment Reporting Information [Line Items]
Contract drilling											$ 145