Supplemental Cash Flow Data (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Cash Flow Data [Abstract]
Income taxes paid, net of refunds	$ 11,613	$ 8,759	$ 1,432
Dividends payable at year end		50,148
Receivable for investment sales proceeds		3,280
Impairment of equity method investment		1,871
Noncash contributions by noncontrolling interests	$ 1,210	$ 183	$ 87