Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Fair value assets and liabilities measured on recurring basis

The following tables set forth our financial assets and liabilities as of December 31, 2017 and 2016 that we measured at fair value on a recurring basis by level within the fair value hierarchy. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to their fair value measurement.

	Fair Value as of December 31, 2017		Fair Value Measurements at December 31, 2017 Using Fair Value Hierarchy
			Level 1		Level 2		Level 3		Valuation Technique
Assets:
Cash and cash equivalents	$	211,922	$	211,922	$	—	$	—	Market
Restricted cash and cash equivalents	21,935		21,935		—		—		Market
Derivative assets	3,254		—		3,254		—		Market
Total	$	237,111	$	233,857	$	3,254	$	—

	Fair Value as of December 31, 2016		Fair Value Measurements at December 31, 2016 Using Fair Value Hierarchy
			Level 1		Level 2		Level 3		Valuation Technique
Assets:
Cash and cash equivalents	$	455,579	$	455,579	$	—	$	—	Market
Restricted cash and cash equivalents	53,238		53,238		—		—		Market
Derivative assets	5,735		—		5,735		—		Market
Total	$	514,552	$	508,817	$	5,735	$	—

Carrying amounts and fair values of financial instruments

The carrying amounts and fair values of our financial instruments at December 31, 2017 and 2016 are as follows:

	December 31, 2017				December 31, 2016
	Carrying Amount of Liability		Fair Value of Liability		Carrying Amount of Liability		Fair Value of Liability
Credit Facilities	$	175,000	$	175,000	$	—	$	—
Unsecured Term Loan	120,000		120,000		120,000		120,000
ECA Financings	227,491		232,030		305,276		316,285
Bank Financings	634,898		634,132		933,541		925,783
Senior Notes	3,200,000		3,367,245		3,200,000		3,387,125