Common Stock Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2011

Common Stock Incentive Plan [Abstract]

Common stock grant activity

The following table summarizes our common stock grant activity under our Stock Plan. Our common stock grants vest over periods ranging from immediately to 10 years.

	2011					2010					2009
	Number of shares			Weighted  average price(1)		Number of shares			Weighted average price(1)		Number of shares			Weighted average price(1)
Outstanding nonvested shares, beginning of year		924,294		$	19.69		853,234		$	19.14		994,453		$	19.70
Shares granted		247,214			33.94		278,200			28.99		142,860			22.86
Shares vested		(245,487	)		25.26		(206,153	)		23.70		(214,521	)		23.14
Shares forfeited		(495	)		31.37		(987	)		26.03		(69,558	)		25.95
Outstanding nonvested shares, end of year		925,526		$	20.21		924,294		$	19.69		853,234		$	19.14

(1) Grant date fair value.

Stock option activity

The following table summarizes our stock option activity for the years:

	2011					2010					2009
	Number of shares			Weighted average   exercise price		Number of shares			Weighted average exercise price		Number of shares			Weighted average exercise price
Outstanding options, beginning of year		2,454		$	14.70		5,846		$	14.70		21,294		$	13.33
Options exercised		(2,454	)		14.70		(3,392	)		14.70		(15,448	)		12.81
Outstanding and exercisable options, end of year		--		$	--		2,454		$	14.70		5,846		$	14.70