Indebtedness - Summary of Company's Indebtedness (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Debt	$ 610,450	$ 606,082
Senior Notes | Senior Unsecured Notes, 3.75% Note Due 2018
Debt Instrument [Line Items]
Debt	75,000	100,000
Senior Notes | Senior Unsecured Notes, 4.75 Note Due 2021
Debt Instrument [Line Items]
Debt	300,000	300,000
Term Loan, Due in Installments through December 2019
Debt Instrument [Line Items]
Debt	109,375	121,875
Capital Lease Obligations, Related Party
Debt Instrument [Line Items]
Debt	4,703	6,157
Capital Lease Obligations
Debt Instrument [Line Items]
Debt	4,591	5,684
Other Debt
Debt Instrument [Line Items]
Debt	0	3,250
Revolving Credit Agreement | Line of Credit | DAMI Secured Credit Agreement
Debt Instrument [Line Items]
Debt	41,781	0
Revolving Credit Agreement | Line of Credit | Credit Facility, 2014
Debt Instrument [Line Items]
Debt	$ 75,000	$ 69,116