Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended	66 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2011	Jun. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Gross carrying value of goodwill	$ 2,240,000,000		$ 2,240,000,000			$ 2,240,000,000
Accumulated impairment of goodwill	2,080,000,000		2,080,000,000			2,080,000,000
Goodwill impairment charge					$ 2,080,000,000	$ 0
Amortization expense on intangible assets	$ 5,155,000	$ 4,120,000	$ 10,310,000	$ 10,445,000
Trademarks | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life			3 years
Trademarks | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life			9 years