|
Condensed Consolidated Balance Sheets (Parenthetical)
|
Jun. 30, 2014
|
Dec. 31, 2013
|
Jun. 30, 2014
Class A ordinary shares, U.S. [Member]
USD ($)
|
Dec. 31, 2013
Class A ordinary shares, U.S. [Member]
USD ($)
|
Jun. 30, 2014
Common Class B, Par Value In GBP [Member]
GBP (£)
|
Dec. 31, 2013
Common Class B, Par Value In GBP [Member]
GBP (£)
|
|---|---|---|---|---|---|---|
| Common stock, par value per share (in dollars per share or pounds sterling per share) | $ 0.10 | $ 0.10 | £ 1 | £ 1 | ||
| Common shares, shares authorized (in shares) | 450,000,000 | 450,000,000 | 50,000 | 50,000 | ||
| Common shares, shares issued (in shares) | 240,600,000 | 239,500,000 | 50,000 | 50,000 | ||
| Treasury shares, shares held (in shares) | 6,300,000 | 6,000,000 |