Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 5,891	$ 5,683	$ 5,497
Charged to operations	3,673	1,819	1,829
Credited to operations	0	0	0
Written off	(1,838)	(1,611)	(1,669)
Effect of exchange rate changes or Other adjustments	0	0	26
Balance at end of year	7,726	5,891	5,683
Deferred Tax Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	228,417	318,055	190,848
Charged to operations	0	0	76,125
Credited to operations	0	0	(38,646)
Written off	(166,911)	(83,115)	0
Effect of exchange rate changes or Other adjustments	(5,718)	(22,119)	0
Balance at end of year	70,940	228,417	318,055
Valuation allowance and reserves, other adjustments	15,152	15,596	12,436
Allowance for Deferred Site Rental Receivables [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	0	5,080	3,600
Charged to operations	0	0	7,200
Credited to operations	0	(5,080)	(5,720)
Written off	0	0	0
Effect of exchange rate changes or Other adjustments	0	0	0
Balance at end of year	$ 0	$ 0	$ 5,080