Restructuring Activities - Additional Information (Detail) (USD $)			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Canonsburg, Pennsylvania Person	Dec. 31, 2012 Tulsa, Oklahoma Person	Dec. 31, 2013 Accounts Payable and Accrued Liabilities	Dec. 31, 2013 Other Noncurrent Liabilities
Restructuring Cost and Reserve [Line Items]
Organization restructuring, termination of employees			30	40
Restructuring and related costs in 2013			$ 2,700,000
Restructuring and related costs in 2014			2,800,000
Restructuring and related costs in 2015			2,800,000
Restructuring and related costs in 2016			2,800,000
Restructuring and related costs in 2017			2,800,000
Restructuring and related costs due 2018 - 2022			10,300,000
Restructuring reserve, current					2,700,000
Restructuring reserve, noncurrent	$ 13,245,000	$ 14,333,000				$ 13,400,000