Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Allowance for Doubtful Accounts Receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 5,683		$ 5,497		$ 6,267
Charged to operations	1,819		1,829		998
Acquired	0		0		0
Credited to operations	0		0		0
Written off	(1,611)		(1,669)		(1,802)
Effect of exchange rate changes or Other adjustments	0		26		34
Balance at end of year	5,891		5,683		5,497
Allowance for Deferred Site Rental Receivables [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	5,080		3,600		0
Charged to operations	0		7,200		3,600
Acquired	0		0		0
Credited to operations	(5,080)		(5,720)		0
Written off	0		0		0
Effect of exchange rate changes or Other adjustments	0		0		0
Balance at end of year	0		5,080		3,600
Deferred Tax Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	318,055		190,848		256,325
Charged to operations	0		76,125		0
Charged to additional paid-in-capital and other comprehensive income	0		38,646		0
Credited to operations	(83,115)		0		(32,761)
Credited to additional paid-in-capital and other comprehensive income	(22,119)		0		(45,657)
Effect of exchange rate changes or Other adjustments	15,596	[1]	12,436	[1]	12,941	[1]
Balance at end of year	$ 228,417		$ 318,055		$ 190,848

[1] Inclusive of the effects of exchange rate changes.