Debt - Consolidated Net Leverage Ratio (Detail) - Credit Agreement	12 Months Ended
	Dec. 31, 2016
Covenant Term 1
Line of Credit Facility [Line Items]
Commitment fee percentage	0.25%
Covenant Term 1 | Eurodollar Loans
Line of Credit Facility [Line Items]
Interest margin	1.75%
Covenant Term 1 | LIBOR
Line of Credit Facility [Line Items]
Interest margin	1.75%
Covenant Term 1 | Letter of Credit Fee
Line of Credit Facility [Line Items]
Interest margin	1.75%
Covenant Term 1 | Base Rate
Line of Credit Facility [Line Items]
Interest margin	0.75%
Covenant Term 1 | Maximum
Line of Credit Facility [Line Items]
Consolidated Net Leverage Ratio	1.50
Covenant Term 2
Line of Credit Facility [Line Items]
Commitment fee percentage	0.30%
Covenant Term 2 | Eurodollar Loans
Line of Credit Facility [Line Items]
Interest margin	2.00%
Covenant Term 2 | LIBOR
Line of Credit Facility [Line Items]
Interest margin	2.00%
Covenant Term 2 | Letter of Credit Fee
Line of Credit Facility [Line Items]
Interest margin	2.00%
Covenant Term 2 | Base Rate
Line of Credit Facility [Line Items]
Interest margin	1.00%
Covenant Term 2 | Minimum
Line of Credit Facility [Line Items]
Consolidated Net Leverage Ratio	1.50
Covenant Term 2 | Maximum
Line of Credit Facility [Line Items]
Consolidated Net Leverage Ratio	2.00
Covenant Term 3
Line of Credit Facility [Line Items]
Commitment fee percentage	0.30%
Covenant Term 3 | Eurodollar Loans
Line of Credit Facility [Line Items]
Interest margin	2.25%
Covenant Term 3 | LIBOR
Line of Credit Facility [Line Items]
Interest margin	2.25%
Covenant Term 3 | Letter of Credit Fee
Line of Credit Facility [Line Items]
Interest margin	2.25%
Covenant Term 3 | Base Rate
Line of Credit Facility [Line Items]
Interest margin	1.25%
Covenant Term 3 | Minimum
Line of Credit Facility [Line Items]
Consolidated Net Leverage Ratio	2.00
Covenant Term 3 | Maximum
Line of Credit Facility [Line Items]
Consolidated Net Leverage Ratio	2.50
Covenant Term 4
Line of Credit Facility [Line Items]
Commitment fee percentage	0.35%
Covenant Term 4 | Eurodollar Loans
Line of Credit Facility [Line Items]
Interest margin	2.50%
Covenant Term 4 | LIBOR
Line of Credit Facility [Line Items]
Interest margin	2.50%
Covenant Term 4 | Letter of Credit Fee
Line of Credit Facility [Line Items]
Interest margin	2.50%
Covenant Term 4 | Base Rate
Line of Credit Facility [Line Items]
Interest margin	1.50%
Covenant Term 4 | Minimum
Line of Credit Facility [Line Items]
Consolidated Net Leverage Ratio	2.50
Covenant Term 4 | Maximum
Line of Credit Facility [Line Items]
Consolidated Net Leverage Ratio	3.00
Covenant Term 5
Line of Credit Facility [Line Items]
Commitment fee percentage	0.40%
Covenant Term 5 | Eurodollar Loans
Line of Credit Facility [Line Items]
Interest margin	2.75%
Covenant Term 5 | LIBOR
Line of Credit Facility [Line Items]
Interest margin	2.75%
Covenant Term 5 | Letter of Credit Fee
Line of Credit Facility [Line Items]
Interest margin	2.75%
Covenant Term 5 | Base Rate
Line of Credit Facility [Line Items]
Interest margin	1.75%
Covenant Term 5 | Minimum
Line of Credit Facility [Line Items]
Consolidated Net Leverage Ratio	3.00