Fair Value Measurements (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended					3 Months Ended
	Mar. 31, 2012	Mar. 31, 2012 Under Commitment To Sell [Member] Mutual Fund [Member]	Dec. 31, 2011 Under Commitment To Sell [Member] Mutual Fund [Member]	Mar. 31, 2012 Under Commitment To Sell [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2011 Under Commitment To Sell [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2012 Not Under Commitment To Sell [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2011 Not Under Commitment To Sell [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2011 Maximum [Member]	Mar. 31, 2011 Minimum [Member]
Schedule Of Fair Value Measurements [Line Items]
Mortgage loans held-for-sale				$ 8,500,000	$ 800,000	$ 46,500,000	$ 77,500,000
Marketable Securities, Unrealized Gain (Loss)		4,300,000
Held-to-maturity Securities, Transferred to Trading Securities, Unrealized Gain (Loss)		700,000	7,200,000
Inventory impairments	$ 300,000
Discount rate used in estimated discounted cash flows								18.00%	13.00%