Basis of Condensed Consolidated Financial Statements (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Concentration Risk, Customer	.404	.391
Common stock, par value	$ 0.00001		$ 0.00001
Escrow deposit	$ 2,400.0		$ 228.9
Minimum [Member]
Escrow deposits, period held by the Company (in business days)	2 days
Maximum [Member]
Escrow deposits, period held by the Company (in business days)	5 days
Wells Fargo [Member]
Concentration Risk, Customer	.106	.091