Interim Financial Statements (Details 2) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Summary of fair value of subordinated notes
Net carrying amount of the liability component	$ 716,807	$ 779,878
7.75% senior subordinated notes due 2016 [Member]
Summary of fair value of subordinated notes
Net carrying amount of the liability component	375,000	375,000
Net fair amount of the liability component	382,969
3.5% senior subordinated convertible notes due 2026 [Member]
Summary of fair value of subordinated notes
Net carrying amount of the liability component	63,324	148,884
Net fair amount of the liability component	$ 64,970

Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date. May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 7

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20, 22
-Article 5

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant