Related Party Transactions (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Related Party Transaction [Line Items]
Related party expenses	$ 2,565	$ 2,160
Base management fees incurred but not yet paid	2,565		2,628
Limited Liability Company [Member]
Related Party Transaction [Line Items]
Rate of management fees	1.50%
Period of termination	180 days
Period to be considered, for average annual base management fee	3
Limited Liability Company [Member] \| Management Fees [Member]
Related Party Transaction [Line Items]
Related party expenses	2,565	2,160
Base management fees incurred but not yet paid	2,565		2,628
Limited Liability Company [Member] \| Reimbursements [Member]
Related Party Transaction [Line Items]
Related party expenses	$ 107	$ 226