Supplemental Balance Sheet Information - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, at beginning of year	$ 14,524	$ 19,307	$ 3,441
Bad debt expense	1,083	6,369	21,911
Write-offs and adjustments	(9,509)	(11,152)	(6,045)
Balance, at end of year	6,098	14,524	19,307
Corrosion Protection
Allowance for Doubtful Accounts Receivable [Roll Forward]
Bad debt expense		2,900
Infrastructure Solutions
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, at beginning of year	7,500	7,500
Balance, at end of year		7,500	7,500
Restructuring Plan 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Bad debt expense	$ (600)	$ 1,200	$ 11,900