Commitments and Other Contingencies (Detail) ft² in Thousands, a in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015 USD ($) ft²	Dec. 31, 2015 USD ($) a ft²	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2008 ft²
Operating Leased Assets [Line Items]
Restructuring Reserve	$ (1,049,000)	$ (1,049,000)	$ (2,367,000)
operating lease future payments, 2015	2,696,000	2,696,000
operating lease future payments, 2016	2,738,000	2,738,000
operating lease future payments, 2016	1,706,000	1,706,000
operating lease future payments, 2018	170,000	170,000
operating lease future payments, 2019	174,000	174,000
operating lease future payments, thereafter	59,000	59,000
Restructuring Charges		(3,797,000)
Payments for Restructuring		5,115,000
Office Facilities And Other Equipment [Member]
Operating Leased Assets [Line Items]
Lease expense		$ 3,872,000	2,617,000	$ 2,374,000
Ground Water Lease [Member]
Operating Leased Assets [Line Items]
Remaining years of timber lease		2 years
Timber land area taken on lease | a		20
Remaining contractual obligation	1,009,000	$ 1,009,000
Corporate Headquarters [Member]
Operating Leased Assets [Line Items]
Net Rentable Area | ft²					32
Remaining contractual obligation	4,212,000	4,212,000
Other Office Locations [Member]
Operating Leased Assets [Line Items]
Remaining contractual obligation	$ 2,269,000	$ 2,269,000
Other Office Locations [Member] | Texas [Member]
Operating Leased Assets [Line Items]
Net Rentable Area | ft²	21	21
Facility Closing [Member]
Operating Leased Assets [Line Items]
Restructuring Reserve	$ 0	$ 0	0
Restructuring Charges		(1,750,000)
Payments for Restructuring		1,750,000
Special Termination Benefits [Member] | Oil and Gas [Member]
Operating Leased Assets [Line Items]
Restructuring Reserve	(1,049,000)	(1,049,000)	$ (2,367,000)
Restructuring Charges		(2,047,000)
Payments for Restructuring		3,365,000
Other Restructuring [Member] | Leasehold Improvements [Member]
Operating Leased Assets [Line Items]
Restructuring Charges		(391,000)
Deferred Lease Revenue [Member]
Operating Leased Assets [Line Items]
Restructuring Charges		364,000
General and Administrative Expense [Member] | One-time Termination Benefits [Member]
Operating Leased Assets [Line Items]
Restructuring Charges		$ (3,314,000)
General and Administrative Expense [Member] | Special Termination Benefits [Member]
Operating Leased Assets [Line Items]
Payments for Restructuring	$ 2,732,000