Commitments and Contingencies, Guarantees and Indemnifications (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Guarantees [Abstract]
Assets held as collateral	$ 0	$ 0
Indemnification Agreement | Obligations Under Sale Of Sharyland
Guarantees [Abstract]
Guarantees issued and outstanding	37,100,000	37,100,000
Guarantor Obligations, Current Carrying Value	400,000	400,000
Payment or Performance Guarantee
Guarantees [Abstract]
Guarantees issued and outstanding	18,300,000	19,400,000
Current exposure under these guarantees	300,000	300,000
Payment or Performance Guarantee | Surety Bonds
Guarantees [Abstract]
Guarantees issued and outstanding	$ 32,400,000	$ 32,100,000