Shareholders' Equity - Schedule of Annualized Dividend Rate (Detail)	12 Months Ended
	Dec. 31, 2013
Preferred Units [Line Items]
Annualized dividend rate	90.00%
August 4, 2011 - September 30, 2011 [Member]
Preferred Units [Line Items]
Annualized dividend rate	1.535%
October 1, 2011 - December 31, 2011 [Member]
Preferred Units [Line Items]
Annualized dividend rate	1.00%
January 1, 2012 - March 31, 2012 [Member]
Preferred Units [Line Items]
Annualized dividend rate	1.00%
April 1, 2012 - June 30, 2012 [Member]
Preferred Units [Line Items]
Annualized dividend rate	1.00%
July 1, 2012 - December 31, 2013 [Member] | Minimum [Member]
Preferred Units [Line Items]
Annualized dividend rate	1.00%
July 1, 2012 - December 31, 2013 [Member] | Maximum [Member]
Preferred Units [Line Items]
Annualized dividend rate	5.00%
January 1, 2014 - February 3, 2016 [Member] | Minimum [Member]
Preferred Units [Line Items]
Annualized dividend rate	1.00%
January 1, 2014 - February 3, 2016 [Member] | Maximum [Member]
Preferred Units [Line Items]
Annualized dividend rate	7.00%
February 4, 2016 - Redemption [Member]
Preferred Units [Line Items]
Annualized dividend rate	9.00%