Stock Transactions and Unit Redemptions - Additional Information (Detail) (USD $)	12 Months Ended	3 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended
	Dec. 31, 2013	Jun. 30, 2013 Global Partnership Restructuring Program [Member]	Dec. 31, 2013 Global Partnership Restructuring Program [Member]	Jul. 30, 2013 Class A Common Stock [Member]	Dec. 31, 2013 Class A Common Stock [Member]	Dec. 31, 2012 Class A Common Stock [Member]	Dec. 31, 2011 Class A Common Stock [Member]	Jul. 27, 2011 Class A Common Stock [Member]	Jun. 30, 2013 Class A Common Stock [Member] Global Partnership Restructuring Program [Member]	Dec. 31, 2013 Class A Common Stock [Member] Controlled Equity Offerings [Member]
Class of Stock [Line Items]
Payment percentage of the gross proceeds from the sale of shares	2.00%
Maximum number of shares under the controlled equity offering					20,000,000
Common stock, shares issued					202,671,000	141,955,000		995,911	44,000,000	10,640,638
Company's repurchase and additional redemption authority amount				$ 250,000,000
Stock repurchase program and unit redemption remaining authorized amount	$ 212,062,601				$ 212,000,000
Redemption of partner units		76,000,000	76,000,000
Common stock granted		44,000,000			1,053,842	4,797,177	3,829,176
Common stock issued, restricted shares		41,000,000	41,000,000