Supplemental Guarantor Information - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2013
Debt Disclosure [Abstract]
Percentage of equity owned by parent in subsidiaries	100.00%
Maximum percentage of net worth of guarantor being released to entity consolidate net worth	5.00%
Maximum percentage of net worth of guarantor being released from guarantor to entity consolidated net worth	10.00%
Maximum percentage of net worth of guarantor being released from guarantor if permitted to entity consolidated net worth	15.00%