Segment Information (Schedule of Revenues from External Customers and Long-Lived Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended						3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Oct. 19, 2012 Drilling Services Division [Member] drilling_rigs	Sep. 30, 2012 Drilling Services Division [Member]	Sep. 30, 2011 Drilling Services Division [Member]	Sep. 30, 2012 Drilling Services Division [Member] Colombia [Member]	Sep. 30, 2011 Drilling Services Division [Member] Colombia [Member]	Sep. 30, 2012 Drilling Services Division [Member] Colombia [Member]	Sep. 30, 2011 Drilling Services Division [Member] Colombia [Member]	Oct. 19, 2012 Drilling Services Division [Member] Colombia [Member] drilling_rigs	Sep. 30, 2012 Drilling Services Division [Member] Colombia [Member] Drilling rigs and equipment [Member] drilling_rigs	Sep. 30, 2011 Drilling Services Division [Member] Colombia [Member] Drilling rigs and equipment [Member] drilling_rigs	Sep. 30, 2012 Drilling Services Division [Member] Colombia [Member] Assets Leased From Others [Member] drilling_rigs	Sep. 30, 2011 Drilling Services Division [Member] Colombia [Member] Assets Leased From Others [Member] drilling_rigs
Revenues from External Customers and Long-Lived Assets [Line Items]
Indentifiable assets	$ 1,303,184	$ 946,888	$ 1,303,184	$ 946,888	$ 1,172,754		$ 837,887	$ 645,104	$ 153,309	$ 154,255	$ 153,309	$ 154,255
Revenues	$ 229,773	$ 187,651	$ 691,575	$ 512,285					$ 24,405	$ 27,990	$ 70,706	$ 81,465
Drilling Rigs						68							8	5	5	3	3