|
Condensed Consolidated Balance Sheets (Parenthetical)
|
Mar. 31, 2011
|
Dec. 31, 2010
|
Mar. 31, 2011
Common Class A Par Value In USD [Member]
USD ($)
|
Dec. 31, 2010
Common Class A Par Value In USD [Member]
USD ($)
|
Mar. 31, 2011
Common Class B, Par Value In GBP [Member]
GBP (£)
|
Dec. 31, 2010
Common Class B, Par Value In GBP [Member]
GBP (£)
|
|---|---|---|---|---|---|---|
| Common shares, par value | $ 0.1 | $ 0.1 | £ 1 | £ 1 | ||
| Common shares, shares authorized | 450,000,000 | 450,000,000 | 50,000 | 50,000 | ||
| Common shares, shares issued | 150,000,000 | 150,000,000 | 50,000 | 50,000 | ||
| Treasury shares, shares held | 6,600,000 | 7,100,000 |