Debt - Covenant Ratios (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Dividends limit	95.00%
Leverage ratio required to trigger dividends limit	6.0
Credit Agreement
Debt Instrument [Line Items]
Net total lease adjusted leverage ratio	5.6	5.4
Net secured debt lease adjusted leverage ratio	2.6	2.6
Fixed charge coverage ratio	5.5	5.7
Fixed charge coverage ratio	2.4	2.5
Credit Agreement | Maximum
Debt Instrument [Line Items]
Net total lease adjusted leverage ratio	6.5	6.5
Net secured debt lease adjusted leverage ratio	4.0	4.0
Fixed charge coverage ratio	6.5	6.5
Credit Agreement | Minimum
Debt Instrument [Line Items]
Fixed charge coverage ratio	1.5	1.5