Stock and Common Stock Warrants (Narrative) (Detail) (USD $)	1 Months Ended		9 Months Ended			1 Months Ended						1 Months Ended
	Sep. 30, 2012	Aug. 31, 2010	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Mar. 28, 2012 First Five Years [Member]	Mar. 28, 2012 Thereafter [Member]	Jan. 23, 2009 US Treasury Securities [Member]	Jan. 23, 2009 Warrant [Member] US Treasury Securities [Member]	Sep. 24, 2009 Peninsula Investment Partners L P [Member]	Sep. 24, 2009 Peninsula Investment Partners L P [Member] Common Stock (Member)	Sep. 24, 2009 Peninsula Investment Partners L P [Member] Common Stock Warrants (Member)	Sep. 24, 2009 Peninsula Investment Partners L P [Member] Warrant [Member]
Equity [Line Items]
Underwritten public offering common stock		1,370,000
Underwritten public offering common stock per share		$ 36.50
Premium of public offering common stock		$ 47,100,000	$ (1,086,000)	$ (914,000)
Cost of public offering common stock		2,900,000
Sale of common stock, shares	18,314,319,000		18,314,319,000		18,258,714,000					862,069
Total purchase price								52,600,000		25,000,000	23,500,000	1,500,000
Warrant to purchase of common stock, shares													129,310
Warrant to purchase of common stock, exercise price									$ 45.08				$ 29.00
Warrant period to purchase									10 years				10 years
Business Acquisition Cost Of Acquired Entity Purchase Price								52,600,000				25,000,000
Issue of preferred stock, shares	52,625,000		52,625,000		52,625,000			52,625
Warrant to purchase of common stock, shares									175,105
Percentage of dividend paid annually for five years						5.00%	9.00%
Preferred stock dividend paid			2,000,000
Total purchase price of preferred stock								51,900,000
Common stock warrants								693,000
Preferred stock accretion	185,000		104,000
Repurchase of stock warrant			$ 1,800,000