Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other assets:
Long-term investments	$ 327,282	$ 332,452
Deferred charges	125,190	149,092
Other	91,749	95,579
Total	544,221	577,123
Accounts payable and accrued liabilities:
Accounts payable	302,113	268,527
Customer deposits	665,339	661,167
Employee related liabilities	255,893	319,963
Miscellaneous other	224,976	323,314
Total	$ 1,448,321	$ 1,572,971