Operations by Business Segment and Geographic Area - Revenues and Long-Lived Assets by Location (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries	$ 2,180,381	$ 1,827,376	$ 1,318,049
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Entity's Country of Domicile	1,106,638	955,228	874,614
Revenues	3,287,019	2,782,604	2,192,663
Long-Lived Assets	1,642,363	1,522,287	1,378,104
Foreign [Member]
Segment Reporting Information [Line Items]
Long-Lived Assets	950,959	914,715	825,465
Norway [Member]
Segment Reporting Information [Line Items]
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries	461,915	461,863	310,891
Long-Lived Assets	429,603	474,408	436,043
West Africa [Member]
Segment Reporting Information [Line Items]
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries	696,202	505,541	316,051
Long-Lived Assets	186,865	141,927	120,732
United Kingdom [Member]
Segment Reporting Information [Line Items]
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries	383,397	334,319	256,565
Long-Lived Assets	99,250	85,434	65,830
Asia and Australia [Member]
Segment Reporting Information [Line Items]
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries	335,129	290,821	217,094
Long-Lived Assets	83,885	65,012	72,518
Brazil [Member]
Segment Reporting Information [Line Items]
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries	213,282	164,660	155,532
Long-Lived Assets	112,840	113,829	99,709
Other [Member]
Segment Reporting Information [Line Items]
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Foreign Countries	90,456	70,172	61,916
Long-Lived Assets	38,516	34,105	30,633
United States [Member]
Segment Reporting Information [Line Items]
Long-Lived Assets	$ 691,404	$ 607,572	$ 552,639