Borrowings - Additional Information (Detail)	3 Months Ended		12 Months Ended						1 Months Ended		3 Months Ended			3 Months Ended								1 Months Ended				3 Months Ended				3 Months Ended			1 Months Ended		3 Months Ended			3 Months Ended				3 Months Ended	1 Months Ended		3 Months Ended				1 Months Ended		3 Months Ended				3 Months Ended
	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Dec. 31, 2012 USD ($)	Dec. 02, 2009 9.125% Senior Secured Notes Due 2016 USD ($)	Dec. 09, 2010 8.875% Senior Secured Notes Due 2016	Dec. 02, 2009 8.875% Senior Secured Notes Due 2016 EUR (€)	Dec. 09, 2010 Additional Debt USD ($)	Dec. 09, 2010 Additional Debt EUR (€)	Mar. 31, 2008 Convertible Senior Notes Due 2013 USD ($)	Mar. 07, 2008 Convertible Senior Notes Due 2013 USD ($)	Mar. 31, 2013 Convertible Senior Notes Due 2013 USD ($)	Mar. 31, 2012 Convertible Senior Notes Due 2013 USD ($)	Dec. 31, 2012 Convertible Senior Notes Due 2013 USD ($)	Mar. 31, 2013 Convertible Note USD ($) Tranche	Mar. 31, 2013 Senior Notes due March 18, 2013 (New Debt) USD ($)	Dec. 31, 2012 Senior Notes due March 18, 2013 (New Debt) USD ($)	Mar. 31, 2013 Senior Notes due March 18, 2013 (New Debt) Roust Trading Limited USD ($)	Mar. 31, 2013 RTL Credit Facility USD ($)	Mar. 31, 2013 RTL Credit Facility Roust Trading Limited USD ($)	Mar. 01, 2013 RTL Credit Facility Roust Trading Limited USD ($)	Mar. 31, 2013 RTL Credit Facility Term Loan Roust Trading Limited USD ($)	Jan. 04, 2010 Senior Secured Notes due 2016 USD ($)	Jan. 04, 2010 Senior Secured Notes due 2016 EUR (€)	Dec. 09, 2010 Senior Secured Notes due 2016	Dec. 02, 2009 Senior Secured Notes due 2016 8.875% Senior Secured Notes Due 2016 USD ($)	Mar. 31, 2013 Overdraft Facility	Aug. 02, 2012 Overdraft Facility USD ($)	Aug. 02, 2012 Overdraft Facility HUF	Mar. 31, 2013 Russian Standard Bank USD ($)	Mar. 31, 2013 Russian Standard Bank Loan Agreement USD ($)	Mar. 31, 2013 Russian Standard Bank Loan Agreement RUB	Mar. 31, 2013 Alfa Bank Tranche	Jul. 31, 2008 Alfa Bank Loan Agreement USD ($)	Jul. 31, 2008 Alfa Bank Loan Agreement EUR (€)	Mar. 31, 2013 Alfa Bank Loan Agreement USD ($)	Mar. 31, 2013 Alfa Bank Loan Agreement RUB	Mar. 31, 2013 Alfa Bank Loan Agreement EUR (€)	Mar. 31, 2013 Alfa Bank Loan Agreement Minimum	Mar. 31, 2013 Alfa Bank Loan Agreement Maximum	Mar. 31, 2013 Zenit Bank, Alfa Bank And Raiffeisen Bank USD ($)	Mar. 31, 2013 Zenit Bank, Alfa Bank And Raiffeisen Bank EUR (€)	Mar. 31, 2013 Zenit Bank Tranche	Aug. 31, 2012 Zenit Bank Loan Agreement USD ($)	Aug. 31, 2012 Zenit Bank Loan Agreement EUR (€)	Mar. 31, 2013 Zenit Bank Loan Agreement USD ($)	Mar. 31, 2013 Zenit Bank Loan Agreement EUR (€)	Mar. 31, 2013 Zenit Bank Loan Agreement Minimum	Mar. 31, 2013 Zenit Bank Loan Agreement Maximum	Oct. 30, 2012 Raiffeisen Bank Loan Agreement USD ($)	Oct. 30, 2012 Raiffeisen Bank Loan Agreement EUR (€)	Mar. 31, 2013 Raiffeisen Bank Loan Agreement USD ($) Tranche	Mar. 31, 2013 Raiffeisen Bank Loan Agreement EUR (€) Tranche	Mar. 31, 2013 Unicredit And JSC Grand Invest Bank Loan Agreement USD ($)	Mar. 31, 2013 Unicredit And JSC Grand Invest Bank Loan Agreement RUB	Mar. 31, 2013 JSC Grand Invest Bank Loan Agreement Term Loan One USD ($)	Mar. 31, 2013 JSC Grand Invest Bank Loan Agreement Term Loan One RUB	Mar. 31, 2013 JSC Grand Invest Bank Loan Agreement Term Loan Two USD ($)	Mar. 31, 2013 JSC Grand Invest Bank Loan Agreement Term Loan Two RUB	Mar. 31, 2013 Sberbank Loan Agreement USD ($)	Mar. 31, 2013 Sberbank Loan Agreement RUB	Mar. 31, 2013 Moscow Credit Bank Loan Agreement USD ($)	Mar. 31, 2013 Moscow Credit Bank Loan Agreement RUB	Mar. 31, 2013 Credit Facility Roust Trading Limited USD ($)
Line of Credit Facility [Line Items]
Outstanding liability																		$ 20,000,000	$ 50,800,000																$ 24,400,000		€ 19,000,000			$ 39,000,000	€ 30,400,000				$ 8,200,000	€ 6,400,000					$ 6,400,000	€ 5,000,000	$ 40,300,000	1,251,000,000	$ 3,500,000	110,000,000	$ 4,900,000	150,000,000	$ 16,800,000	520,000,000
Initiation date																										August 2, 2012				February 27, 2013	February 27, 2013		July 22, 2008	July 22, 2008									August 16, 2012	August 16, 2012					October 26, 2012	October 26, 2012					November 25, 2011	November 25, 2011	December 19, 2012	December 19, 2012	November 23, 2012	November 23, 2012
Maturity date											March 15, 2013															August 1, 2013				February 27, 2014	February 27, 2014		October 18, 2014	October 18, 2014									April 25, 2014	April 25, 2014					September 30, 2013	September 30, 2013					November 23, 2013	November 23, 2013	November 22, 2013	November 22, 2013	November 22, 2013	November 22, 2013
Maximum borrowing capacity																											2,100,000	500,000,000	15,100,000	15,100,000	465,000,000		25,600,000	20,000,000									12,800,000	10,000,000					6,400,000	5,000,000
Loan agreement, number of tranches														6																		16										3									4	4
Date of tranches release, start date																																			October 12, 2012	October 12, 2012									January 28, 2013	January 28, 2013					October 29, 2012	October 29, 2012
Date of tranches release, end date																																			February 28, 2013	February 28, 2013									March 11, 2013	March 11, 2013					November 20, 2012	November 20, 2012
Repayable date																																						April 12,2013	October 28, 2013								October 25, 2013	March 7, 2014			September 30, 2013	September 30, 2013
Outstanding liability including accrued interest																															469,700,000																													521,400,000
Term loan facility utilized portion																											1,500,000	350,100,000
Interest expense related party	904,000	0																																																													800,000
Loan agreement repaid	729,300,000		590,900,000																																23,300,000	724,000,000																									29,000,000	900,000,000
Debt instrument issuance amount	50,000,000		0	380,000,000		380,000,000	64,100,000	50,000,000		310,000,000					70,000,000				50,000,000	50,000,000	50,000,000				487,100,000
Interest rate percentage on issued debt				9.125%	8.875%	9.125%				3.00%					3.00%				3.00%						8.875%
Year of maturity of debt										2013
Initial conversion rate shares										14.7113
Principal amount of initial conversion rate										1,000
Repurchased amount of convertible notes														52,100,000
Principal amount of convertible notes														50,200,000
Debt defaulted, principal amount											257,900,000						20,000,000
Debt defaulted, accrued interest											4,200,000
Debt defaulted, fair value											58,000,000		138,100,000		21,100,000	70,400,000
Liability component of convertible senior Notes	257,858,000		256,922,000							290,300,000
Equity component of convertible senior Notes										19,700,000
Discount rate used to calculate present value									4.50%
Equity component recorded as additional paid-in capital									12,800,000
Deferred income taxes	719,000	1,488,000							6,900,000
Pre tax non-cash interest expense recognized in consolidated statement of operations and comprehensive income											800,000	1,100,000
Accumulated amortization related to the debt discount											19,700,000		18,900,000
Redemption of senior secured notes																						314,600,000	245,400,000
Debt instrument maturity year																								2016
Accrued interest	27,900,000		7,100,000																																																												800,000
Common stock to be purchased, price per share															$ 5.25
Debt instrument maturity date															Mar. 18, 2013
Common stock to be purchased, shares															13,300,000
Common stock price per share for interest payable on debt security															$ 3.44
Accrued Interest Payments On Notes															1,100,000
Accumulated unamortized debt discount															$ 12,700,000	$ 13,600,000