Segment Information (Schedule of Revenues from External Customers and Long-Lived Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended							3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Apr. 20, 2012 Drilling Services Division [Member] drilling_rigs	Mar. 31, 2012 Drilling Services Division [Member] drilling_rigs	Mar. 30, 2012 Drilling Services Division [Member] drilling_rigs	Mar. 31, 2011 Drilling Services Division [Member]	Mar. 31, 2012 Drilling Services Division [Member] Colombia [Member]	Mar. 31, 2011 Drilling Services Division [Member] Colombia [Member]	Apr. 20, 2012 Drilling Services Division [Member] Colombia [Member] drilling_rigs	Mar. 31, 2012 Drilling Services Division [Member] Colombia [Member] Drilling rigs and equipment [Member] drilling_rigs	Mar. 31, 2011 Drilling Services Division [Member] Colombia [Member] Drilling rigs and equipment [Member] drilling_rigs	Mar. 31, 2012 Drilling Services Division [Member] Colombia [Member] Assets Leased From Others [Member] drilling_rigs	Mar. 31, 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	$ 1,199,084	$ 847,987	$ 1,172,754		$ 745,072		$ 581,725	$ 152,854	$ 157,285
Revenues	$ 231,978	$ 153,349						$ 23,816	$ 24,234
Drilling Rigs				62	62	64				8	5	5	3	3