Shareholders' Equity - Additional Information (Detail) (USD $)	12 Months Ended				12 Months Ended								12 Months Ended																12 Months Ended
	Dec. 31, 2012 installments	Dec. 31, 2011	Dec. 31, 2010	Dec. 09, 2012	Dec. 31, 2012 Stock Options [Member]	Dec. 31, 2011 Stock Options [Member]	Dec. 31, 2010 Stock Options [Member]	Dec. 31, 2012 Stock Options [Member] 2008 Omnibus Plan [Member]	Dec. 31, 2010 Stock Options [Member] 2008 Omnibus Plan [Member]	Dec. 31, 2009 Stock Options [Member] 2008 Omnibus Plan [Member]	May 25, 2011 Stock Options [Member] 2008 Omnibus Plan [Member]	May 23, 2008 Stock Options [Member] 2008 Omnibus Plan [Member]	Dec. 31, 2012 Stock Options [Member] Prior Plans [Member]	Dec. 31, 2012 Stock Options [Member] Employee Stock [Member]	Dec. 31, 2011 Stock Options [Member] Employee Stock [Member]	Dec. 31, 2010 Stock Options [Member] Employee Stock [Member]	Dec. 31, 2012 Restricted Stock [Member]	Dec. 31, 2012 Performance Shares [Member]	Dec. 31, 2012 Performance Shares [Member] Employee Stock [Member]	Dec. 31, 2012 Restricted Stock Units [Member]	Dec. 31, 2011 Restricted Stock Units [Member]	Dec. 31, 2010 Restricted Stock Units [Member]	Dec. 31, 2012 2008 Employee Stock Purchase Plan [Member]	Dec. 31, 2011 2008 Employee Stock Purchase Plan [Member]	Dec. 31, 2010 2008 Employee Stock Purchase Plan [Member]	Dec. 31, 2012 Capital Stock [Member]	Dec. 31, 2011 Capital Stock [Member]	May 23, 2008 Maximum Stock Options [Member] 2008 Omnibus Plan [Member]	Dec. 31, 2012 Options Granted Prior To Year Two Thousand And Eleven [Member] Stock Options [Member] 2008 Omnibus Plan [Member]	Dec. 31, 2012 Options Granted In Year Two Thousand And Eleven [Member] Stock Options [Member] 2008 Omnibus Plan [Member]	Dec. 31, 2011 Director [Member] Stock Options [Member]	Dec. 31, 2010 Director [Member] Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Merger Consideration, Right to Receive Cash for Stock, Price Per Share				$ 10.00
Total intrinsic value of stock options exercised			$ 1,000,000
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	0.0	1,000,000	600,000																	600,000	1,000,000	300,000	100,000
Common Stock, Shares Authorized	250,000,000	250,000,000									5,600,000												3,000,000	1,500,000		250,000,000
Common Stock, Shares Authorized, Increase																							1,500,000
Number of anti-dilutive stock options excluded from calculation of diluted earnings (loss) per share	3,268,152	4,316,869	3,616,015
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant								3,800,000				8,414,363																4,764,363
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	621,605							4,618,273					1,010,103	621,605					227,780
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value														$ 2.76	$ 3.84	$ 4.68															$ 4.48	$ 5.09
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period													5 years					3 years		3 years									4 years	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	7 years												10 years																10 years	7 years
Reduction In Number Of Stock Options And Restricted Deferred Stock Units That Would Be Granted Percentage									75.00%	25.00%
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized					3,900,000												8,600,000	300,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition					1 year 11 months 11 days												1 year 10 months 1 day	1 year 0 months 16 days
Stock options exercised and other	(425,000)	223,000	259,000		100,000	200,000	600,000
Performance Period, Years																		3 years
Performance Target, Minimum, Percentage																		0.00%
Performance Target, Maximum, Percentage																		200.00%
Common Stock Purchase Limit To Authorize Payroll Deduction, Maximum, Value																							25,000
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date																							85.00%
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date																							15.00%
Share-based Compensation	6,784,000	11,296,000	8,955,000		6,784,000	10,939,000	8,569,000																400,000	300,000	200,000
Compensation expense recognition period	3
Common Stock, Par or Stated Value Per Share																										$ 0.01
Preferred Stock, Shares Authorized																										50,000,000
Preferred Stock, Par or Stated Value Per Share																										$ 0.01
Common Stock, shares outstanding	60,354,000	59,717,000																								60,353,839	59,717,242
Stock Repurchased During Period, Value		10,019,000	20,037,000
Stock Repurchased During Period, Shares	0	936,533	1,835,865
Treasury Stock Acquired, Average Cost Per Share		$ 10.68	$ 10.89
Stock Repurchase Program, Authorized Amount			75,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Vesting Installments	4
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 45,000,000