Stockholders' Equity - Reclassifications out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
General and Administrative Expense	$ (26,925)	$ (22,808)	$ (23,704)
Amounts reclassified from accumulated other comprehensive income (loss)	2,519	$ 0
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)	2,634
Amounts reclassified from accumulated other comprehensive income (loss) related to forward starting swaps [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
General and Administrative Expense	115
Amounts reclassified from accumulated other comprehensive loss arising from settlement of defined benefit pension plan [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
General and Administrative Expense	$ 2,519