Goodwill and Other Intangible Assets (Changes in Carrying Amount of Goodwill) (Detail) - Jun. 30, 2015 - USD ($) $ in Thousands	Total
Goodwill [Line Items]
Balance as of December 31, 2014	$ 78,011
Balance as of June 30, 2015	81,877
Completion and Remedial Services
Goodwill [Line Items]
Balance as of December 31, 2014	78,011
Goodwill adjustments	3,866
Balance as of June 30, 2015	$ 81,877