Earnings per Share - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 25, 2014	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2014 5.25% Convertible Notes, Due 2014 [Member]	Jun. 30, 2014 5.25% Convertible Notes, Due 2014 [Member]	Jun. 30, 2013 Convertible Notes [Member]	Jun. 30, 2014 Convertible Notes [Member]	Jun. 30, 2013 Convertible Notes [Member]	Jun. 30, 2013 Stock Awards [Member]	Jun. 30, 2014 Stock Awards [Member]	Jun. 30, 2013 Stock Option [Member]	Jun. 30, 2014 Stock Option [Member]	Jun. 30, 2014 Equity Unit Purchase Agreements [Member]	Jun. 30, 2013 Equity Unit Purchase Agreements [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of shares, option exercised						89,000,000
Number of shares that become outstanding							89,000,000
Number of weighted average outstanding shares included in both basic and diluted shares							56,000,000
Weighted Average number of shares outstanding dilutive effect	6,000,000				2,000,000		89,000,000
Number of weighted average outstanding diluted shares	1,189,000,000	1,069,000,000		1,137,000,000	1,079,000,000		33,000,000
Number of anti-dilutive securities								89,000,000	33,000,000	89,000,000	17,000,000	19,000,000	9,000,000	31,000,000	3,000,000	48,000,000
Shares that would have been included in diluted earnings per share calculation								89,000,000	33,000,000		8,000,000	10,000,000	1,000,000	6,000,000
Weighted average exercise price of options													$ 10.77	$ 16.24
Number of common stock shares issued in a part of acquisition			36,523,010
Business acquisition common stock issued, price per share			$ 13.69