Acquisitions - Purchase Price Allocation (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014 Black Hawk Energy Services, Inc.	Dec. 16, 2013 Black Hawk Energy Services, Inc. Previously Reported	Sep. 30, 2014 Black Hawk Energy Services, Inc. Measurement Period Adjustments
Accounts receivable				$ 10,114	$ 9,663	$ 451
Prepaid expenses and other current assets				319	208	111
Property and equipment				30,088	30,581	(493)
Intangible assets				12,210	0	12,210
Accounts payable				(1,584)	(1,333)	(251)
Accrued expenses				(2,160)	(1,756)	(404)
Total identifiable net assets acquired				48,987	37,363	11,624
Goodwill	67,530	67,530	53,093	10,576	23,400	(12,824)
Net assets acquired				$ 59,563	$ 60,763	$ (1,200)