Supplementary Balance Sheet Information - Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Supplementary Balance Sheet Information
Deferred revenues	$ 46,120	$ 40,473
Income taxes payable	40,914	1,673
Accrued third-party commissions	33,809	28,310
Accrued expenses	27,226	32,861
Dividends payable	19,252	19,513
Litigation settlements	16,761	20,795
Accrued interest	11,276	19,029
Other	142,790	100,605
Total	$ 338,148	$ 263,259