Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair value assets and liabilities measured on recurring basis:
Marketable equity securities	$ 24,800	$ 17,100
Fair value on a recurring basis | Fair Value
Fair value assets and liabilities measured on recurring basis:
Marketable equity securities	24,829
Total fair value assets and liabilities measured on recurring basis	10,248
Fair value on a recurring basis | Fair Value | Interest-rate swap contracts
Fair value assets and liabilities measured on recurring basis:
Derivative assets	89
Derivative liabilities	(12,699)
Fair value on a recurring basis | Fair Value | Currency swap liabilities
Fair value assets and liabilities measured on recurring basis:
Derivative liabilities	(2,641)
Fair value on a recurring basis | Fair Value | Warrants
Fair value assets and liabilities measured on recurring basis:
Derivative assets	670
Fair value on a recurring basis | Level 1
Fair value assets and liabilities measured on recurring basis:
Marketable equity securities	24,829
Total fair value assets and liabilities measured on recurring basis	24,829
Fair value on a recurring basis | Level 2
Fair value assets and liabilities measured on recurring basis:
Total fair value assets and liabilities measured on recurring basis	(15,251)
Fair value on a recurring basis | Level 2 | Interest-rate swap contracts
Fair value assets and liabilities measured on recurring basis:
Derivative assets	89
Derivative liabilities	(12,699)
Fair value on a recurring basis | Level 2 | Currency swap liabilities
Fair value assets and liabilities measured on recurring basis:
Derivative liabilities	(2,641)
Fair value on a recurring basis | Level 3
Fair value assets and liabilities measured on recurring basis:
Total fair value assets and liabilities measured on recurring basis	670
Fair value on a recurring basis | Level 3 | Warrants
Fair value assets and liabilities measured on recurring basis:
Derivative assets	$ 670