Annual report pursuant to Section 13 and 15(d)

Organization and Business - Schedule of Basic and Diluted Earnings per Share (Parenthetical) (Detail)

v2.4.1.9
Organization and Business - Schedule of Basic and Diluted Earnings per Share (Parenthetical) (Detail)
 12 Months Ended 6 Months Ended
Dec. 31, 2012
Jun. 30, 2013
Diluted weighted average units outstanding, contingently issuable units 146,452us-gaap_IncrementalCommonSharesAttributableToContingentlyIssuableShares  
Class B Common Stock    
Diluted weighted average units outstanding, contingently issuable units   228,549us-gaap_IncrementalCommonSharesAttributableToContingentlyIssuableShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember