Acquisitions (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended								7 Months Ended	12 Months Ended
	May 24, 2015	Oct. 31, 2014	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Acquisitions
Cash paid for acquisitions of businesses												$ 22,278	$ 128,245	$ 72,760
Operating revenues			$ 538,948	$ 519,729	$ 571,591	$ 597,571	$ 738,872	$ 847,553	$ 863,305	$ 1,414,707		$ 2,227,839	3,864,437	6,804,197
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life												2 years
Assets:
Goodwill			166,917				166,659				$ 166,659	$ 166,917	166,659	173,928
Liabilities:
Accrued liabilities							22,278				22,278		22,278
Net income (loss)			(335,587)	$ (111,211)	$ (184,650)	$ (398,294)	$ (163,654)	$ (295,834)	$ (36,821)	$ 123,634		(1,029,742)	(372,675)	(670,659)
Joint Venture in Saudi Arabia
Acquisitions
Ownership percentage	51.00%
Carrying value of equity method investment	$ 44,700
Excess of fair value over carrying value of long-lived assets													2,300
Two T D Drilling
Acquisitions
Cash paid for acquisitions of businesses		$ 40,300
Additional Contingent payments			$ 13,900									$ 13,900
Recorded intangible assets		47,700
Business Combination, Contingent Consideration, Asset, Total		24,700
Assets:
Goodwill		$ 28,100
Joint Venture in Saudi Arabia
Acquisitions
Cash paid for acquisitions of businesses	$ 106,000
Remaining equity interest acquired (as a percent)	49.00%
Operating revenues											248,900
Assets:
Cash	$ 48,058
Accounts receivable	153,819
Other current assets	58,021
Property, plant and equipment, net	89,643
Intangible assets	28,784
Goodwill	75,634
Other long-term assets	7,709
Total assets	461,668
Liabilities:
Accounts payable	206,599
Accrued liabilities	74,393
Intangible liability	13,472
Deferred tax liability	4,823
Other long-term liabilities	9,400
Total liabilities	308,687
Net assets acquired	$ 152,981
Operating revenues													4,035,004	6,953,218
Net income (loss)											$ 6,000
Business Acquisition, Pro Forma Information
Operating revenues													4,035,004	6,953,218
Income (loss) from continuing operations, net of tax													$ (316,633)	$ (668,127)
Income (loss) from continuing operations per share - basic													$ (1.09)	$ (2.27)
Income (loss) from continuing operations per share - diluted													$ (1.09)	$ (2.27)