Other Non-Current Liabilities (Other Non-Current Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Other Liabilities, Noncurrent [Abstract]
Deferred rent liabilitiy	$ 254,494		$ 226,383	[1]
Unearned revenue	164,032		125,472	[1]
Other miscellaneous liabilities	225,175	[1]	220,229	[1]
Balance as of December 31	$ 643,701		$ 572,084	[1]

[1] December 31, 2011 balances have been revised to reflect purchase accounting measurement period adjustments.