Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Line Items]
Percentage of benefit due to valuation allowance release		116.30%
Valuation allowance release, amount		$ 109,800,000
Decrease in effective tax rate due to valuation allowance, percentage		0.60%	37.00%	44.80%
Decrease in effective tax rate due to valuation allowance, amount			$ 51,600,000	$ 77,000,000
Decrease in effective tax rate due to settlement of a federal income tax audit, percentage			2.40%
Increase in effective tax rate				6.80%
Unrecognized tax benefits that would impact effective tax rate	$ 6,400,000	$ 6,400,000	$ 8,000,000
Short-term reserves	600,000	600,000
Long-term reserves	7,100,000	7,100,000
Interest and penalties		$ 1,986,000	2,820,000	$ 3,107,000
Significant change in unrecognized tax benefits, nature of event description		Due to the potential for resolution of federal and state examinations, and the expiration of various statutes of limitations
Gross unrecognized tax benefits change range, minimum	0	$ 0
Gross unrecognized tax benefits change range, maximum	1,000,000	1,000,000
Illinois edge credits available to offset future state income tax		9,800,000
Valuation allowance released	109,800,000
Net deferred income tax assets	47,500,000	47,500,000
Domestic Country [Member]
Income Tax [Line Items]
Net operating loss carry forwards	134,800,000	134,800,000
Operating loss carrybacks	97,500,000	97,500,000
Tax refund due to carryback of losses		14,000,000
Foreign Country [Member]
Income Tax [Line Items]
Foreign tax credits	33,000,000	33,000,000
State and Local Jurisdiction [Member]
Income Tax [Line Items]
Net operating loss carry forwards	319,700,000	319,700,000
Separate State [Member]
Income Tax [Line Items]
Net operating loss carry forwards	$ 166,000,000	166,000,000
Maximum [Member]
Income Tax [Line Items]
Unrecognized tax benefits, income tax penalties and interest benefit/expense recognized		$ 700,000	$ 100,000	$ 700,000
Maximum [Member] | Illinois [Member]
Income Tax [Line Items]
Edge credits expiration year		2019
Maximum [Member] | Domestic Country [Member]
Income Tax [Line Items]
Net operating loss carry forwards, expiration year		2035
Maximum [Member] | Foreign Country [Member]
Income Tax [Line Items]
Foreign tax credits, expiration year		2023
Maximum [Member] | State and Local Jurisdiction [Member]
Income Tax [Line Items]
Net operating loss carry forwards, expiration year		2035
Minimum [Member] | Illinois [Member]
Income Tax [Line Items]
Edge credits expiration year		2016
Minimum [Member] | Domestic Country [Member]
Income Tax [Line Items]
Net operating loss carry forwards, expiration year		2034
Minimum [Member] | Foreign Country [Member]
Income Tax [Line Items]
Foreign tax credits, expiration year		2022
Minimum [Member] | State and Local Jurisdiction [Member]
Income Tax [Line Items]
Net operating loss carry forwards, expiration year		2016