Stock Option Plans And Warrants (Stock Options And Restricted Stock Units Activity) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options Outstanding, Beginning of period	1,300,400	1,481,550	1,350,252
Number of Options, Granted	161,250	82,000	200,625
Number of Options, Exercised	(18,125)	(194,650)	(59,827)
Number of Options, Forfeited	(27,833)	(28,500)	(9,500)
Number of Options, Expired	(93,325)	(40,000)
Number of Options Outstanding, Ending of period	1,322,367	1,300,400	1,481,550
Number of Options, Exercisable	1,044,125	970,450	1,051,550
Weighted-Average Exercise Price Outstanding, Beginning of period	$ 29.06	$ 27.85	$ 28.65
Weighted-Average Exercise Price, Granted	$ 17.14	$ 28.70	$ 19.94
Weighted-Average Exercise Price, Exercised	$ 3.93	$ 18.83	$ 14.27
Weighted-Average Exercise Price, Forfeited	$ 28.80	$ 38.60	$ 60.92
Weighted-Average Exercise Price, Expired	$ 26.85	$ 26.25
Weighted-Average Exercise Price Outstanding, End of period	$ 27.81	$ 29.06	$ 27.85
Weighted-Average Exercise Price, Exercisable	$ 29.27	$ 30.78	$ 23.18
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value Nonvested, Beginning of period	$ 35.82	$ 44.63	$ 51.42
Weighted-Average Grant Date Fair Value, Granted	$ 9.82	$ 27.34	$ 24.89
Weighted-Average Grant Date Fair Value, Vested	$ 43.20	$ 34.66	$ 34.51
Weighted-Average Grant Date Fair Value, Forfeited	$ 16.61	$ 46.81	$ 45.00
Weighted-Average Grant Date Fair Value Nonvested, End of period	$ 15.15	$ 35.82	$ 44.63
Number of Restricted Stock Nonvested, Beginning of period	79,150	79,074	68,555
Number of Restricted Stock, Granted	125,678	49,752	25,009
Number of Restricted Stock, Vested	(31,267)	(22,100)	(2,740)
Number of Restricted Stock, Forfeited	(10,604)	(27,576)	(11,750)
Number of Restricted Stock Nonvested, Ending period	162,957	79,150	79,074
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value Nonvested, Beginning of period	$ 29.84	$ 0.00
Weighted-Average Grant Date Fair Value, Granted	$ 21.01	$ 29.84
Weighted-Average Grant Date Fair Value, Vested	$ 35.01	$ 0.00
Weighted-Average Grant Date Fair Value, Forfeited	$ 29.73	$ 0.00
Weighted-Average Grant Date Fair Value Nonvested, End of period	$ 24.85	$ 29.84
Number of Restricted Stock Nonvested, Beginning of period	46,001	0
Number of Restricted Stock, Granted	47,618	46,001
Number of Restricted Stock, Vested	(1,000)	0
Number of Restricted Stock, Forfeited	(7,501)	0
Number of Restricted Stock Nonvested, Ending period	85,118	46,001