Condensed Consolidated Statements of Comprehensive Operations (Unaudited) (Parenthetical) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Other comprehensive income (loss), net of income tax:
Tax effect of changes in value on available-for-sale securities	$ (4,375,000)	$ 0	$ (1,824,000)	$ 0
Tax for interest rate lock derivative contracts reclassified to income	10,000	10,000	21,000	21,000
Tax for change in fair value of interest rate lock derivative contracts designated as a hedge	$ 0	$ 8,000	$ 0	$ 18,000