Employee Benefit Plans and Shareholder Rights Plan (Tables)

12 Months Ended

Dec. 31, 2011

Employee Benefit Plans and Shareholder Rights Plan [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity

The following is a summary of our stock option activity for the year ended December 31, 2010:

	Shares under Option		Weighted Average Exercise Price		Aggregate Intrinsic Value
Balance at December 31, 2009	82,000		8.44
Granted	—		—
Exercised	(82,000	)	8.44		$	1,858,000
Forfeited	—		—
Balance at December 31, 2010	—		$	—

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

The following is a summary of our restricted stock and restricted stock unit activity for 2012, 2011 and 2010:

	Number		Weighted Average Fair Value		Aggregate Intrinsic Value
Balance at December 31, 2009	1,243,050		$	19.86
Granted	421,850		29.58
Issued	(595,790	)	16.23		$	16,673,000
Forfeited	(24,960	)	24.73
Balance at December 31, 2010	1,044,150		25.74
Granted	463,400		41.26
Issued	(379,952	)	30.81		$	15,563,000
Forfeited	(36,748	)	27.77
Balance at December 31, 2011	1,090,850		30.49
Granted	337,575		55.98
Issued	(369,050	)	20.03		$	20,325,000
Forfeited	(27,803	)	42.02
Balance at December 31, 2012	1,031,572		$	42.27