Related Party Transactions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Related Party Transaction [Line Items]
Related party expenses	$ 2,627	$ 2,625	$ 2,600	$ 2,160	$ 2,040	$ 1,518	$ 1,292	$ 1,289	$ 10,012	$ 6,139	$ 4,728
Base management fees incurred but not yet paid	2,628				2,037				2,628	2,037
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									10,012	6,139	4,728
Base management fees incurred but not yet paid	2,628				2,037				2,628	2,037
Limited Liability Company [Member] \| Reimbursements [Member]
Related Party Transaction [Line Items]
Related party expenses									$ 745	$ 987	$ 802